Tuesday, 17 November 2015

Let the image float to the left/right of a paragraph - HTML Programs

<html>
<body>

<p>
<img src="smiley.gif" alt="Smiley face" style="float:left" width="32" height="32"> A paragraph with an image. The image will float to the left of this text.
</p>

<p>
<img src="smiley.gif" alt="Smiley face" style="float:right" width="32" height="32"> A paragraph with an image. The image will float to the right of this text.
</p>

<p><b>Note:</b> Here we have used the CSS "float" property to align the image; as the align attribute is deprecated in HTML 4, and is not supported in HTML5.</p>

</body>
</html>

Output

A paragraph with an image. The image will float to the left of this text.

A paragraph with an image. The image will float to the right of this text.
Note: Here we have used the CSS "float" property to align the image; as the align attribute is deprecated in HTML 4, and is not supported in HTML5.

Note: Due to inclusion of code to blogpost, images not able to display. But the code will work properly

Aligning images - HTML Programs

<html>
<body>

<h4>Image with default alignment (align="bottom"):</h4>
<p>This is some text. <img src="smiley.gif" alt="Smiley face" width="32" height="32"> This is some text.</p>

<h4>Image with align="middle":</h4>
<p>This is some text. <img src="smiley.gif" alt="Smiley face" align="middle" width="32" height="32"> This is some text.</p>

<h4>Image with align="top":</h4>
<p>This is some text. <img src="smiley.gif" alt="Smiley face" align="top" width="32" height="32"> This is some text.</p>

<p><b>Note:</b> The align attribute is deprecated in HTML 4, and is not supported in HTML5. Use CSS instead.</p>

</body>
</html>

Output

Image with default alignment (align="bottom"):

This is some text.

Image with align="middle":

This is some text.

Image with align="top":

This is some text.

This is some text.
Note: The align attribute is deprecated in HTML 4, and is not supported in HTML5. Use CSS instead.

Note: Due to inclusion of code to blogpost, images not able to display. But the code will work properly

Insert images - HTML Programs

<html>
<body>
<p>
An image:
<img src="html/home.png" alt="home" width="32" height="32"></p>

<p>
A moving image:
<img src="smiley.gif" alt="you are the best" width="48" height="48"></p>

<p>
Note that the syntax of inserting a moving image is no different from a non-moving image.
</p>

</body>
</html>

Output

An image:

A moving image:

Note that the syntax of inserting a moving image is no different from a non-moving image.

Note: Due to inclusion of code to blogpost, images not able to display. But the code will work properly

Wednesday, 3 June 2015

Insert horizontal lines - HTML Programs

<html>

<body>

<p>The hr tag defines a horizontal rule:</p>

<hr><p>This is a paragraph</p>

</body>

</html>

Output

The hr tag defines a horizontal rule:

This is a paragraph

How to mark deleted and inserted text - HTML Programs

<html>
<body>

<p>My favorite color is <del>blue</del> <ins>red</ins>!</p>

<p>Notice that browsers will strikethrough deleted text and underline inserted text.</p>

</body>
</html>

Output

My favorite color is ~~blue~~ red!
Notice that browsers will strikethrough deleted text and underline inserted text.

Text direction - HTML Programs

<html>
<body>
<p>
If your browser supports bi-directional override (bdo), the next line will be written from the right to the left (rtl):
</p>

<bdo dir="rtl">
Here is some Hebrew text
</bdo>
</body>
</html>

Output

If your browser supports bi-directional override (bdo), the next line will be written from the right to the left (rtl):
Here is some Hebrew text

Tuesday, 26 May 2015

Abbreviations and acronyms - HTML Programs

<html>
<body>

<p>The <abbr title="World Health Organization">WHO</abbr> was founded in 1948.</p>
<p>Can I get this <abbr title="as soon as possible">ASAP</abbr>?</p>

<p>The title attribute is used to show the spelled-out version when holding the mouse pointer over the acronym or abbreviation.</p>
</body>
</html>

Output

The WHO was founded in 1948.
Can I get this ASAP?
The title attribute is used to show the spelled-out version when holding the mouse pointer over the acronym or abbreviation.

Insert contact information - HTML Programs

<html>
<body>

<address>
Written by W3Schools.com<br>
<a href="mailto:us@example.org">Email us</a><br>
Address: Box 564, Disneyland<br>
Phone: +12 34 56 78
</address>

</body>
</html>

Output

Written by W3Schools.com
Email us
Address: Box 564, Disneyland
Phone: +12 34 56 78

Computer code
Keyboard input
Sample text
Computer variable
Note: These tags are often used to display computer/programming code.

Preformatted text (how to control line breaks and spaces) - HTML Programs

<html>
<body>

<pre>
This is
preformatted text.
It preserves both spaces
and line breaks.
</pre>
The pre tag is good for displaying computer code:<br />

<pre>
for i = 1 to 10
print i
next i
</pre>
</body>
</html>

Output

This is
preformatted text.
It preserves      both spaces
and line breaks.

The pre tag is good for displaying computer code:

for i = 1 to 10
     print i
next i

Text formatting - HTML Programs

<html>
<body>
<p><b>This text is bold</b></p>
<p><strong>This text is strong</strong></p>
<p><em>This text is emphasized</em></p>
<p><i>This text is italic</i></p>
<p><small>This text is small</small></p>
<p>This is<sub> subscript</sub> and <sup>superscript</sup></p>

</body>
</html>

Output

This text is bold
This text is strong
This text is emphasized
This text is italic
This text is small
This is_subscript and ^superscript

Draw a border around form-data - HTML programs

<html>
<body>

<form action="">
<fieldset>
<legend>Personal information:</legend>
Name: <input type="text" size="30"><br>
E-mail: <input type="text" size="30"><br>
Date of birth: <input type="text" size="10">
</fieldset>
</form>

</body>
</html>

Output

Create a button - HTML Programs

<html>
<body>

<form action="">
<input type="button" value="Hello world!">
</form>

</body>
</html>

Output

Text area (a multi-line text input field) - HTML Programs

<html>
<body>

<textarea rows="10" cols="30">
The cat was playing in the garden.
</textarea>

</body>
</html>

Output

Sunday, 3 May 2015

Drop-down list with a pre-selected value - HTML Programs

<html>
<body>

<form action="">
<select name="cars">
<option value="volvo">Volvo</option>
<option value="saab">Saab</option>
<option value="fiat" selected>Fiat</option>
<option value="audi">Audi</option>
</select>
</form>

</body>
</html>

Output

Simple drop-down list - HTML Programs

<html>
<body>

<form action="">
<select name="cars">
<option value="volvo">Volvo</option>
<option value="saab">Saab</option>
<option value="fiat">Fiat</option>
<option value="audi">Audi</option>
</select>
</form>

</body>
</html>

Output

Radio buttons - HTML Programs

<html>
<body>
<form action="">
<input type="radio" name="sex" value="male">Male<br>
<input type="radio" name="sex" value="female">Female
</form>

<p><b>Note:</b> When a user clicks on a radio-button, it becomes checked, and all other radio-buttons with equal name become unchecked.</p>

</body>
</html>

Output

Note: When a user clicks on a radio-button, it becomes checked, and all other radio-buttons with equal name become unchecked.

Checkboxes - HTML Programs

<html>
<body>
<form action="">
<input type="checkbox" name="vehicle" value="Bike">I have a bike<br>
<input type="checkbox" name="vehicle" value="Car">I have a car
</form>

</body>
</html>

Output

Create password field - HTML Programs

<html>
<body>
<form action="">
Username: <input type="text" name="user"><br>
Password: <input type="password" name="password">
</form>

<p><b>Note:</b> The characters in a password field are masked (shown as asterisks or circles).</p>

</body>
</html>

Output

Note: The characters in a password field are masked (shown as asterisks or circles).

Create text fields - HTML Programs

<html>
<body>

<form action="">
First name: <input type="text" name="firstname"><br>
Last name: <input type="text" name="lastname">
</form>

<p><b>Note:</b> The form itself is not visible. Also note that the default width of a text field is 20 characters.</p>

</body>
</html>

Output

Note: The form itself is not visible. Also note that the default width of a text field is 20 characters.

HTML Images - HTML Programs

<html>
<body>

<img src="home.png" width="104" height="142">
</body>
</html>

Output

Note: Due to inclusion of code to appx file, images not able to display. But the code will work properly

HTML paragraphs - HTML Programs

<html>
<body>

<p>This is a paragraph.</p>
<p>This is a paragraph.</p>
<p>This is a paragraph.</p>

</body>
</html>

Output

This is a paragraph.
This is a paragraph.
This is a paragraph.

HTML headings - HTML Programs

<html>
<body>

<h1>This is heading 1</h1>
<h2>This is heading 2</h2>
<h3>This is heading 3</h3>
<h4>This is heading 4</h4>
<h5>This is heading 5</h5>
<h6>This is heading 6</h6>

</body>
</html>

Output

This is heading 1

This is heading 2

This is heading 3

This is heading 4

This is heading 5

This is heading 6

A very simple HTML document - HTML Programs

<html>
<body>

<h3>My First Heading</h3>

<p>My first paragraph.</p>

</body>
</html>

Output:

My First Heading

My first paragraph.

Monday, 27 April 2015

C Program to find Lucky Number

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
long int sumf(long int x)
{
long int s;
for(s=0;x>0;s+=x%10,x/=10);
return s;
}
void main()
{
long int sum=0;
int a[26],i,k;
char s[99];
l1:
printf("\n Enter your name without spaces:");
gets(s);
for(i=0;i<strlen(s);i++)
{
if(s[i]>=65&&s[i]<=90)
a[i]=s[i]+32;
else
a[i]=s[i];
}
for(i=0;i<strlen(s);i++)
{
if(a[i]<97||a[i]>122)
{
printf("\n Invalid Character Please Try again");
goto l1;
}
}
for(i=0;s[i]!='\0';i++)
sum=sum+a[i];
while(sum>=10)
sum=sumf(sum);
k=sum;
printf("\n\n\n\t Your lucky number\n\t according to the name is : %ld ",sum);
printf("\n\n Enter your date of birth : ");
scanf("%ld",&sum);
while(sum>=10)
sum=sumf(sum);
printf("\n\n\t Your lucky number\n\t according to the date of birth is : %ld ",sum);
if(k==sum)
printf("\n\n\t You are the Luckiest Person");
}

Saturday, 4 April 2015

Tower of Hanoi Solutions upto 10 disks

The Tower of Hanoi (also called the Tower of Brahma or Lucas' Tower, and sometimes pluralized) is a mathematical game or puzzle. It consists of three rods, and a number of disks of different sizes which can slide onto any rod. The puzzle starts with the disks in a neat stack in ascending order of size on one rod, the smallest at the top, thus making a conical shape.

The objective of the puzzle is to move the entire stack to another rod, obeying the following simple rules:

Only one disk can be moved at a time.
Each move consists of taking the upper disk from one of the stacks and placing it on top of another stack i.e. a disk can only be moved if it is the uppermost disk on a stack.
No disk may be placed on top of a smaller disk.

With three disks, the puzzle can be solved in seven moves. The minimum number of moves required to solve a Tower of Hanoi puzzle is 2ⁿ - 1, where n is the number of disks.

Saturday, 24 January 2015

Python Programs - Sending Email using SMTP

Sending Email
Simple Mail Transfer Protocol (SMTP) is a protocol which handles sending e-mail and routing e-mail between mail servers.
Python provides smtplib module which defines an SMTP client session object that can be used to send mail to any Internet machine with an SMTP or ESMTP listener daemon.
Syntax:
import smtplib

smtpObj = smtplib.SMTP( [host [, port [, local_hostname]]] )

Here is the detail of the parameters:
1. host: This is the host running your SMTP server. You can specifiy IP address of the host or a domain name. This is optional argument.
2. port: If you are providing host argument then you need to specifiy a port where SMTP server is listening. Usually this port would be 25.
3. local_hostname: If your SMTP server is running on your local machine then you can specify just localhost as of this option.
An SMTP object has an instance method called sendmail, which will typically be used to do the work of mailing a message.
It takes three parameters:
1. The sender - A string with the address of the sender.
2. The receivers - A list of strings, one for each recipient.
3. The message - A message as a string formatted as specified in the various RFCs.
Example
#!/usr/bin/python

import smtplib

sender = 'from@fromdomain.com'
receivers = ['to@todomain.com']

message = """From: From Person < from@fromdomain.com >
To: To Person < to@todomain.com >
Subject: SMTP e-mail test

This is a test e-mail message.
"""

try:
   smtpObj = smtplib.SMTP('localhost')
   smtpObj.sendmail(sender, receivers, message)
   print "Successfully sent email"
except SMTPException:
   print "Error: unable to send email"

Python Programs - Regular Expressions - Search Function

#!/usr/bin/python
import re

line = "Cats are smarter than dogs";

matchObj = re.search( r'(.*) are(\.*)', line, re.M|re.I)

if matchObj:
   print "matchObj.group() : ", matchObj.group()
   print "matchObj.group(1) : ", matchObj.group(1)
   print "matchObj.group(2) : ", matchObj.group(2)
else:
   print "No match!!"
Output
matchObj.group(): Cats are
matchObj.group(1) : Cats
matchObj.group(2) :

Python Programs - Regular Expressions - Match Function

#!/usr/bin/python
import re

line = "Cats are smarter than dogs";

matchObj = re.match( r'(.*) are(\.*)', line, re.M|re.I)

if matchObj:
   print "matchObj.group() : ", matchObj.group()
   print "matchObj.group(1) : ", matchObj.group(1)
   print "matchObj.group(2) : ", matchObj.group(2)
else:
   print "No match!!"
Output
matchObj.group(): Cats are
matchObj.group(1) : Cats
matchObj.group(2) :

Python Tuples

Accessing Values in Tuples:
#!/usr/bin/python

tup1 = ('physics', 'chemistry', 1997, 2000);
tup2 = (1, 2, 3, 4, 5, 6, 7 );

print "tup1[0]: ", tup1[0]
print "tup2[1:5]: ", tup2[1:5]
Output
tup1[0]: physics
tup2[1:5]: [2, 3, 4, 5]
Updating Tuples:
#!/usr/bin/python

tup1 = (12, 34.56);
tup2 = ('abc', 'xyz');

# Following action is not valid for tuples
# tup1[0] = 100;

# So let's create a new tuple as follows
tup3 = tup1 + tup2;
print tup3;
Output
(12, 34.56, 'abc', 'xyz')
Delete Tuple Elements:
#!/usr/bin/python

tup = ('physics', 'chemistry', 1997, 2000);

print tup;
del tup;
print "After deleting tup : "
print tup;
Output
('physics', 'chemistry', 1997, 2000)
After deleting tup :
Traceback (most recent call last):
File "test.py", line 9, in < module >
print tup;
NameError: name 'tup' is not defined
No Enclosing Delimiters:
#!/usr/bin/python

print 'abc', -4.24e93, 18+6.6j, 'xyz';
x, y = 1, 2;
print "Value of x , y : ", x,y;
print var;
Output
abc -4.24e+93 (18+6.6j) xyz
Value of x , y : 1 2

Python Strings

Accessing Values in Strings:
#!/usr/bin/python

var1 = 'Hello World!'
var2 = "Python Programming"

print "var1[0]: ", var1[0]
print "var2[1:5]: ", var2[1:5]
Output
var1[0]: H
var2[1:5]: ytho
Updating Strings:
#!/usr/bin/python

var1 = 'Hello World!'

print "Updated String :- ", var1[:6] + 'Python'
Output
Updated String :- Hello Python
String Formatting Operator:
#!/usr/bin/python

print "My name is %s and weight is %d kg!" % ('Zara', 21)
Output
My name is Zara and weight is 21 kg!
Triple Quotes:
#!/usr/bin/python

para_str = """this is a long string that is made up of
several lines and non-printable characters such as
TAB ( \t ) and they will show up that way when displayed.
NEWLINEs within the string, whether explicitly given like
this within the brackets [ \n ], or just a NEWLINE within
the variable assignment will also show up.
"""
print para_str;
Output
this is a long string that is made up of
several lines and non-printable characters such as
TAB ( ) and they will show up that way when displayed.
NEWLINEs within the string, whether explicitly given like
this within the brackets [
], or just a NEWLINE within
the variable assignment will also show up.
Raw String:
#!/usr/bin/python

print 'C:\\nowhere'
Output
C:\nowhere
Unicode String:
#!/usr/bin/python

print u'Hello, world!'
Output
Hello, world!

Python Lists

Accessing Values in Lists:
#!/usr/bin/python

list1 = ['physics', 'chemistry', 1997, 2000];
list2 = [1, 2, 3, 4, 5, 6, 7 ];

print "list1[0]: ", list1[0]
print "list2[1:5]: ", list2[1:5]
Output
list1[0]: physics
list2[1:5]: [2, 3, 4, 5]
Updating Lists:
#!/usr/bin/python

list = ['physics', 'chemistry', 1997, 2000];

print "Value available at index 2 : "
print list[2];
list[2] = 2001;
print "New value available at index 2 : "
print list[2];
Output
Value available at index 2 :
1997
New value available at index 2 :
2001
Delete List Elements:
#!/usr/bin/python

list1 = ['physics', 'chemistry', 1997, 2000];

print list1;
del list1[2];
print "After deleting value at index 2 : "
print list1;
Output
['physics', 'chemistry', 1997, 2000]
After deleting value at index 2 :
['physics', 'chemistry', 2000]

Python Files I/O

Reading Keyboard Input:
Python provides two built-in functions to read a line of text from standard input, which by default comes from the keyboard. These functions are:
raw_input

input
- The raw_input Function:
  #!/usr/bin/python
  
  str = raw_input("Enter your input: ");
  print "Received input is : ", str
  Output
  Enter your input: Hello Python
  Received input is : Hello Python
- The input Function:
  #!/usr/bin/python
  
  str = input("Enter your input: ");
  print "Received input is : ", str
  Output
  Enter your input: [x*5 for x in range(2,10,2)]
  Recieved input is : [10, 20, 30, 40]
Opening and Closing Files:

Syntax:
file object = open(file_name [, access_mode][, buffering])

Here is paramters detail:
1. file_name: The file_name argument is a string value that contains the name of the file that you want to access.
2. access_mode: The access_mode determines the mode in which the file has to be opened ie. read, write append etc. A complete list of possible values is given below in the table. This is optional parameter and the default file access mode is read (r)
3. buffering: If the buffering value is set to 0, no buffering will take place. If the buffering value is 1, line buffering will be performed while accessing a file. If you specify the buffering value as an integer greater than 1, then buffering action will be performed with the indicated buffer size. If negative, the buffer size is the system default(default behavior).
The file object atrributes:
#!/usr/bin/python

# Open a file
fo = open("foo.txt", "wb")
print "Name of the file: ", fo.name
print "Closed or not : ", fo.closed
print "Opening mode : ", fo.mode
print "Softspace flag : ", fo.softspace
Output
Name of the file: foo.txt
Closed or not : False
Opening mode : wb
Softspace flag : 0
The close() Method:

Syntax:
fileObject.close();
#!/usr/bin/python

# Open a file
fo = open("foo.txt", "wb")
print "Name of the file: ", fo.name

# Close opend file
fo.close()
Output
Name of the file: foo.txt
Reading and Writing Files:
- The write() Method:
  The write() method writes any string to an open file. It is important to note that Python strings can have binary data and not just text.
  
  The write() method does not add a newline character ('\n') to the end of the string:
  Syntax:
  fileObject.write(string);
  
  Here passed parameter is the content to be written into the opend file.
  Example:
  #!/usr/bin/python
  
  # Open a file
  fo = open("foo.txt", "wb")
  fo.write( "Python is a great language.\nYeah its great!!\n");
  
  # Close opend file
  fo.close()
  
  The above method would create foo.txt file and would write given content in that file and finally it would close that file. If you would open this file, it would have following content
  
  Python is a great language.
  Yeah its great!!
- The read() Method:
  
  Syntax:
  fileObject.read([count]);
  #!/usr/bin/python
  
  # Open a file
  fo = open("foo.txt", "r+")
  str = fo.read(10);
  print "Read String is : ", str
  # Close opend file
  fo.close()
  
  This would produce following result:
  
  Read String is : Python is
File Positions:
#!/usr/bin/python

# Open a file
fo = open("foo.txt", "r+")
str = fo.read(10);
print "Read String is : ", str

# Check current position
position = fo.tell();
print "Current file position : ", position

# Reposition pointer at the beginning once again
position = fo.seek(0, 0);
str = fo.read(10);
print "Again read String is : ", str
# Close opend file
fo.close()
This would produce following result:

Read String is : Python is
Current file position : 10
Again read String is : Python is
Renaming and Deleting Files:
- The rename() Method:
  The rename() method takes two arguments, the current filename and the new filename.
  Syntax:
  os.rename(current_file_name, new_file_name)
  Example:
  Following is the example to rename an existing file test1.txt:
  
  #!/usr/bin/python
  import os
  
  # Rename a file from test1.txt to test2.txt
  os.rename( "test1.txt", "test2.txt" )
- The delete() Method:
  
  Syntax:
  os.delete(file_name)
  Example:
  Following is the example to delete an existing file test2.txt:
  
  #!/usr/bin/python
  import os
  
  # Delete file test2.txt
  os.delete("text2.txt")
Directories in Python:
- The mkdir() Method:
  
  Syntax:
  os.mkdir("newdir")
  Example:
  Following is the example to create a directory test in the current directory:
  
  #!/usr/bin/python
  import os
  
  # Create a directory "test"
  os.mkdir("test")
- The chdir() Method:
  
  Syntax:
  os.chdir("newdir")
  Example:
  Following is the example to go into "/home/newdir" directory:
  
  #!/usr/bin/python
  import os
  
  # Changing a directory to "/home/newdir"
  os.chdir("/home/newdir")
- The getcwd() Method:
  
  Syntax:
  os.getcwd()
  Example:
  
  Following is the example to give current directory:
  #!/usr/bin/python
  import os
  
  # This would give location of the current directory
  os.getcwd()
- The rmdir() Method:
  
  Syntax:
  
  os.rmdir('dirname')
  Example:
  Following is the example to remove "/tmp/test" directory. It is required to give fully qualified name of the directory otherwise it would search for that directory in the current directory.
  
  #!/usr/bin/python
  import os
  
  # This would remove "/tmp/test" directory.
  os.rmdir( "/tmp/test" )

Python Dictionary

Accessing Values in Dictionary:
#!/usr/bin/python
dict = {'Name': 'Zara', 'Age': 7, 'Class': 'First'};

print "dict['Name']: ", dict['Name'];
print "dict['Age']: ", dict['Age'];
Output
dict['Name']: Zara
dict['Age']: 7
Updating Dictionary:
#!/usr/bin/python
dict = {'Name': 'Zara', 'Age': 7, 'Class': 'First'};

dict['Age'] = 8; # update existing entry
dict['School'] = "DPS School"; # Add new entry

print "dict['Age']: ", dict['Age'];
print "dict['School']: ", dict['School'];
Output
dict['Age']: 8
dict['School']: DPS School
Delete Dictionary Elements:
#!/usr/bin/python

dict = {'Name': 'Zara', 'Age': 7, 'Class': 'First'};

del dict['Name']; # remove entry with key 'Name'
dict.clear(); # remove all entries in dict
del dict ; # delete entire dictionary

print "dict['Age']: ", dict['Age'];
print "dict['School']: ", dict['School'];
Output
This will produce following result. Note an exception raised, this is because after del dict dictionary does not exist any more:

dict['Age']:
Traceback (most recent call last):
File "test.py", line 8, in < module >
print "dict['Age']: ", dict['Age'];
TypeError: 'type' object is unsubscriptable
Properties of Dictionary Keys:
(a) More than one entry per key not allowed. Which means no duplicate key is allowed. When duplicate keys encountered during assignment, the last assignment wins. Following is a simple example:

#!/usr/bin/python

dict = {'Name': 'Zara', 'Age': 7, 'Name': 'Manni'};

print "dict['Name']: ", dict['Name'];

When the above code is executed, it produces following result:

dict['Name']: Manni

(b) Keys must be immutable. Which means you can use strings, numbers, or tuples as dictionary keys but something like ['key'] is not allowed. Following is a simple example:

#!/usr/bin/python

dict = {['Name']: 'Zara', 'Age': 7};

print "dict['Name']: ", dict['Name'];

When the above code is executed, it produces following result:

Traceback (most recent call last):
File "test.py", line 3, in < module >
dict = {['Name']: 'Zara', 'Age': 7};
TypeError: list objects are unhashable

Python Date/Time

What is Tick?
Python's time and calendar modules help track dates and times.
Time intervals are floating-point numbers in units of seconds.
Particular instants in time are expressed in seconds since 12:00am, January 1, 1970(epoch).
There is a popular time module available in Python which provides functions for working with times, and for converting between representations. The function time.time() returns the current system time in ticks since 12:00am, January 1, 1970(epoch).
Example:
#!/usr/bin/python
import time; # This is required to include time module.

ticks = time.time()
print "Number of ticks since 12:00am, January 1, 1970:", ticks

This would produce a result something as follows:

Number of ticks since 12:00am, January 1, 1970: 7186862.73399
Getting current time -:
#!/usr/bin/python
localtime = time.localtime(time.time())
print "Local current time :", localtime
Output
Local current time : (2008, 5, 15, 12, 55, 32, 0, 136, 1)
Getting formatted time -:
#!/usr/bin/python
import time;

localtime = time.asctime( time.localtime(time.time()) )
print "Local current time :", localtime
Output
Local current time : Tue Jan 13 10:17:09 2009
Getting calendar for a month -:
#!/usr/bin/python
import calendar

cal = calendar.month(2008, 1)
print "Here is the calendar:"
print cal;
Output
Here is the calendar:
January 2008
Mo Tu We Th Fr Sa Su
1 2 3 4 5 6
7 8 9 10 11 12 13
14 15 16 17 18 19 20
21 22 23 24 25 26 27
28 29 30 31

Python Object Oriented - Overriding Methods

#!/usr/bin/python

class Parent: # define parent class
   def myMethod(self):
     print 'Calling parent method'

class Child(Parent): # define child class
   def myMethod(self):
     print 'Calling child method'

c = Child() # instance of child
c.myMethod() # child calls overridden method
Output
Calling child method

Python Object Oriented - Overloading Operators

#!/usr/bin/python

class Vector:
   def __init__(self, a, b):
     self.a = a
     self.b = b

   def __str__(self):
     return 'Vector (%d, %d)' % (self.a, self.b)
   def __add__(self,other):
     return Vector(self.a + other.a, self.b + other.b)

v1 = Vector(2,10)
v2 = Vector(5,-2)
print v1 + v2
Output
Vector(7,8)

Python Object Oriented - Data Hiding

#!/usr/bin/python

class JustCounter:
   __secretCount = 0

   def count(self):
     self.__secretCount += 1
     print self.__secretCount

counter = JustCounter()
counter.count()
counter.count()
print counter.__secretCount
Output
1
2
Traceback (most recent call last):
File "test.py", line 12, in < module >
print counter.__secretCount
AttributeError: JustCounter instance has no attribute '__secretCount'
Python protects those members by internally changing the name to include the class name. You can access such attributes as object._className__attrName. If you would replace your last line as following, then it would work for you:

.........................
print counter._JustCounter__secretCount
Output
1
2
2

Python Object Oriented - Class Inheritance

#!/usr/bin/python

class Parent: # define parent class
parentAttr = 100
def __init__(self):
   print "Calling parent constructor"

def parentMethod(self):
   print 'Calling parent method'

def setAttr(self, attr):
   Parent.parentAttr = attr

def getAttr(self):
   print "Parent attribute :", Parent.parentAttr

class Child(Parent): # define child class
def __init__(self):
   print "Calling child constructor"

def childMethod(self):
   print 'Calling child method'
c = Child() # instance of child
c.childMethod() # child calls its method
c.parentMethod() # calls parent's method
c.setAttr(200) # again call parent's method
c.getAttr() # again call parent's method
Output
Calling child constructor
Calling child method
Calling parent method
Parent attribute : 200
Similar way you can drive a class from multiple parent classes as follows:

class A: # define your class A
.....

class B: # define your calss B
.....

class C(A, B): # subclass of A and B
.....

Python Object Oriented - Classes

Creating Classes:
The class statement creates a new class definition. The name of the class immediately follows the keyword class followed by a colon as follows:
class ClassName:
'Optional class documentation string'
class_suite

The class has a documentation string which can be access via ClassName.__doc__.

The class_suite consists of all the component statements, defining class members, data attributes, and functions.
Example:
class Employee:
'Common base class for all employees'
empCount = 0

def __init__(self, name, salary):
   self.name = name
   self.salary = salary
   Employee.empCount += 1

def displayCount(self):
   print "Total Employee %d" % Employee.empCount

def displayEmployee(self):
   print "Name : ", self.name, ", Salary: ", self.salary
Creating instance objects:
"This would create first object of Employee class"
emp1 = Employee("Zara", 2000)
"This would create second object of Employee class"
emp2 = Employee("Manni", 5000)
Accessing attributes:
You access the object's attributes using the dot operator with object. Class variable would be accessed using class name as follows:

emp1.displayEmployee()
emp2.displayEmployee()
print "Total Employee %d" % Employee.empCount

Python Programs - Multithreading - Synchronizing Threads:

Synchronization
#!/usr/bin/python

import threading
import time

class myThread (threading.Thread):
   def __init__(self, threadID, name, counter):
     self.threadID = threadID
     self.name = name
     self.counter = counter
     threading.Thread.__init__(self)
   def run(self):
     print "Starting " + self.name
     # Get lock to synchronize threads
     threadLock.acquire()
     print_time(self.name, self.counter, 3)
     # Free lock to release next thread
     threadLock.release()

  def print_time(threadName, delay, counter):
     while counter:
       time.sleep(delay)
       print "%s: %s" % (threadName, time.ctime(time.time()))
       counter -= 1

threadLock = threading.Lock()
threads = []

# Create new threads
thread1 = myThread(1, "Thread-1", 1)
thread2 = myThread(2, "Thread-2", 2)

# Start new Threads
thread1.start()
thread2.start()

# Add threads to thread list
threads.append(thread1)
threads.append(thread2)

# Wait for all threads to complete
for t in threads:
   t.join()
print "Exiting Main Thread"
Output
Starting Thread-1
Starting Thread-2
Thread01: Thu Jan 22 16:04:38 2009
Thread01: Thu Jan 22 16:04:39 2009
Thread01: Thu Jan 22 16:04:40 2009
Thread02: Thu Jan 22 16:04:42 2009
Thread02: Thu Jan 22 16:04:44 2009
Thread02: Thu Jan 22 16:04:46 2009
Exiting Main Thread

Python Multithreaded Programming

Starting a New Thread
#!/usr/bin/python

import thread
import time

# Define a function for the thread
def print_time( threadName, delay):
   count = 0
   while count < 5:
     time.sleep(delay)
     count += 1
     print "%s: %s" % ( threadName, time.ctime(time.time()) )

# Create two threads as follows
try:
   thread.start_new_thread( print_time, ("Thread-1", 2, ) )
   thread.start_new_thread( print_time, ("Thread-2", 4, ) )
except:
   print "Error: unable to start thread"

while 1:
   pass
Output
Thread-1: Thu Jan 22 15:42:17 2009
Thread-1: Thu Jan 22 15:42:19 2009
Thread-2: Thu Jan 22 15:42:19 2009
Thread-1: Thu Jan 22 15:42:21 2009
Thread-2: Thu Jan 22 15:42:23 2009
Thread-1: Thu Jan 22 15:42:23 2009
Thread-1: Thu Jan 22 15:42:25 2009
Thread-2: Thu Jan 22 15:42:27 2009
Thread-2: Thu Jan 22 15:42:31 2009
Thread-2: Thu Jan 22 15:42:35 2009

Python Program - Creating Thread using Threading Module

Threading Module
#!/usr/bin/python

import threading
import time

exitFlag = 0

class myThread (threading.Thread):
   def __init__(self, threadID, name, counter):
     self.threadID = threadID
     self.name = name
     self.counter = counter
     threading.Thread.__init__(self)
   def run(self):
     print "Starting " + self.name
     print_time(self.name, self.counter, 5)
     print "Exiting " + self.name
def print_time(threadName, delay, counter):
   while counter:
     if exitFlag:
       thread.exit()
       time.sleep(delay)
       print "%s: %s" % (threadName, time.ctime(time.time()))
       counter -= 1

# Create new threads
thread1 = myThread(1, "Thread-1", 1)
thread2 = myThread(2, "Thread-2", 2)

# Start new Threads
thread1.start()
thread2.run()

while thread2.isAlive():
   if not thread1.isAlive():
     exitFlag = 1
   pass
  print "Exiting Main Thread"
Output
Starting Thread-2
Starting Thread-1
Thread-1: Thu Jan 22 15:53:05 2009
Thread-2: Thu Jan 22 15:53:06 2009
Thread-1: Thu Jan 22 15:53:06 2009
Thread-1: Thu Jan 22 15:53:07 2009
Thread-2: Thu Jan 22 15:53:08 2009
Thread-1: Thu Jan 22 15:53:08 2009
Thread-1: Thu Jan 22 15:53:09 2009
Exiting Thread-1
Thread-2: Thu Jan 22 15:53:10 2009
Thread-2: Thu Jan 22 15:53:12 2009
Thread-2: Thu Jan 22 15:53:14 2009
Exiting Thread-2
Exiting Main Thread

Python Functions

def functionname( parameters ):
  "function_docstring"
  function_suite
  return [expression]
Example
def printme( str ):
  "This prints a passed string into this function"
  print str
  return

#!/usr/bin/python

# Function definition is here
def printme( str ):
  "This prints a passed string into this function"
  print str;
  return;

# Now you can call printme function
printme("I'm first call to user defined function!");
printme("Again second call to the same function");
Output
I'm first call to user defined function!
Again second call to the same function
Pass by reference vs value:
#!/usr/bin/python

# Function definition is here
def changeme( mylist ):
   "This changes a passed list into this function"
   mylist.append([1,2,3,4]);
   print "Values inside the function: ", mylist
   return

# Now you can call changeme function
mylist = [10,20,30];
changeme( mylist );
print "Values outside the function: ", mylist
Output
Values inside the function: [10, 20, 30, [1, 2, 3, 4]]
Values outside the function: [10, 20, 30, [1, 2, 3, 4]]

There is one more example where argument is being passed by reference but inside the function, but the reference is being over-written.
#!/usr/bin/python
# Function definition is here
def changeme( mylist ):
   "This changes a passed list into this function"
   mylist = [1,2,3,4]; # This would assig new reference in mylist
   print "Values inside the function: ", mylist
   return
# Now you can call changeme function
mylist = [10,20,30];
changeme( mylist );
print "Values outside the function: ", mylist
Output
Values inside the function: [1, 2, 3, 4]
Values outside the function: [10, 20, 30]

Python Programs - Function Arguments

You can call a function by using the following types of formal arguments::
Required arguments

Keyword arguments

Default arguments

Variable-length arguments
Required arguments:
To call the function printme() you definitely need to pass one argument otherwise it would give a syntax error as follows:

#!/usr/bin/python

# Function definition is here
def printme( str ):
   "This prints a passed string into this function"
   print str;
   return;

# Now you can call printme function
printme();
Output
Traceback (most recent call last):
File "test.py", line 11, in < module >
printme();
TypeError: printme() takes exactly 1 argument (0 given)
Keyword arguments:
This allows you to skip arguments or place them out of order because the Python interpreter is able to use the keywords provided to match the values with parameters.
You can also make keyword calls to the printme() function in the following ways:

#!/usr/bin/python

# Function definition is here
def printme( str ):
   "This prints a passed string into this function"
  print str;
  return;

# Now you can call printme function
printme( str = "My string");
Output
My string
Default arguments:
#!/usr/bin/python

# Function definition is here
def printinfo( name, age = 35 ):
"This prints a passed info into this function"
print "Name: ", name;
print "Age ", age;
return;

# Now you can call printinfo function
printinfo( age=50, name="miki" );
printinfo( name="miki" );
Output
Name: miki
Age 50
Name: miki
Age 35
Variable-length arguments:

Syntax:
def functionname([formal_args,] *var_args_tuple ):
"function_docstring"
function_suite
return [expression]

Example:
#!/usr/bin/python

# Function definition is here
def printinfo( arg1, *vartuple ):
"This prints a variable passed arguments"
print "Output is: "
print arg1
for var in vartuple:
print var
return;

# Now you can call printinfo function
printinfo( 10 );
printinfo( 70, 60, 50 );
Output
Output is:
10
Output is:
70
60
50

Python Programs - Database - Update Operation:

Update Table
#!/usr/bin/python

import MySQLdb

# Open database connection
db = MySQLdb.connect("localhost","testuser","test123","TESTDB" )

# prepare a cursor object using cursor() method
cursor = db.cursor()

# Prepare SQL query to UPDATE required records
sql = "UPDATE EMPLOYEE SET AGE = AGE + 1
     WHERE SEX = '%c'" % ('M')
try:
   # Execute the SQL command
   cursor.execute(sql)
   # Commit your changes in the database
   db.commit()
except:
   # Rollback in case there is any error
   db.rollback()

# disconnect from server
db.close()

Python Program - Database - READ Operation

READ Operation
READ Operation on any databasse means to fetch some useful information from the database.
Once our database connection is established, we are ready to make a query into this database.
We can use either fetchone() method to fetch single record or fetchall method to fetech multiple values from a database table.
1. fetchone(): This method fetches the next row of a query result set.
  A result set is an object that is returned when a cursor object is used to query a table.
2. fetchall(): This method fetches all the rows in a result set.
  If some rows have already been extracted from the result set, the fetchall() method retrieves the remaining rows from the result set.
3. rowcount: This is a read-only attribute and returns the number of rows that were affected by an execute() method.
Example:
Following is the procedure to query all the records from EMPLOYEE table having salary more than 1000.

#!/usr/bin/python

import MySQLdb

# Open database connection
db = MySQLdb.connect("localhost","testuser","test123","TESTDB" )

# prepare a cursor object using cursor() method
cursor = db.cursor()

# Prepare SQL query to INSERT a record into the database.
sql = "SELECT * FROM EMPLOYEE \
   WHERE INCOME > '%d'" % (1000)
try:
   # Execute the SQL command
   cursor.execute(sql)
   # Fetch all the rows in a list of lists.
   results = cursor.fetchall()
   for row in results:
     fname = row[0]
     lname = row[1]
     age = row[2]
     sex = row[3]
     income = row[4]
     # Now print fetched result
     print "fname=%s,lname=%s,age=%d,sex=%s,income=%d" % \
     (fname, lname, age, sex, income )
except:
   print "Error: unable to fecth data"
# disconnect from server
db.close()

This will produce following result:

fname=Mac, lname=Mohan, age=20, sex=M, income=2000

Python Program - Database - Performing Transactions:

Transaction
Transactions are a mechanism that ensures data consistency. Transactions should have the following four properties:
1. Atomicity: Either a transaction completes or nothing happens at all.
2. Consistency: A transaction must start in a consistent state and leave the system is a consistent state.
3. Isolaion: Intermediate results of a transaction are not visible outside the current transaction.
4. Durability: Once a transaction was committed, the effects are persistent, even after a system failure.
5. The Python DB API 2.0 provides two methods to either commit or rollback a transaction.
Example:
# Prepare SQL query to DELETE required records
sql = "DELETE FROM EMPLOYEE WHERE AGE > '%d'" % (20)
try:
   # Execute the SQL command
   cursor.execute(sql)
   # Commit your changes in the database
   db.commit()
except:
   # Rollback in case there is any error
   db.rollback()
COMMIT Operation:
Commit is the operation which gives a green signal to database to finalize the changes and after this operation no change can be reverted back.
Example
db.commit()
ROLLBACK Operation:
If you are not satisfied with one or more of the changes and you want to revert back those changes completely then use rollback method.
Example
db.rollback()
Disconnecting Database:
To disconnect Database connection, use close() method.
db.close()

If the connection to a database is closed by the user with the close() method, any outstanding transactions are rolled back by the DB.
However, instead of depending on any of DB lower level implementation details, your application would be better off calling commit or rollback explicitly.

Pages

Auto AdSense

Tuesday, 17 November 2015

Output

Note: Due to inclusion of code to blogpost, images not able to display. But the code will work properly

Image with default alignment (align="bottom"):

Image with align="middle":

Image with align="top":

Note: Due to inclusion of code to blogpost, images not able to display. But the code will work properly

Wednesday, 3 June 2015

Tuesday, 26 May 2015

Sunday, 3 May 2015

This is heading 1

This is heading 2

This is heading 3

This is heading 4

This is heading 5

This is heading 6

My First Heading

Monday, 27 April 2015

Saturday, 4 April 2015

Saturday, 24 January 2015

Sending Email

Syntax:

Example

Output

Output

Accessing Values in Tuples:

Output

Updating Tuples:

Output

Delete Tuple Elements:

Output

No Enclosing Delimiters:

Output

Accessing Values in Strings:

Output

Updating Strings:

Output

String Formatting Operator:

Output

Triple Quotes:

Output

Raw String:

Output

Unicode String:

Output

Accessing Values in Lists:

Output

Updating Lists:

Output

Delete List Elements:

Output

Reading Keyboard Input:

raw_input

input

The raw_input Function:

Output

The input Function:

Output

Opening and Closing Files:

Syntax:

The file object atrributes:

Output

The close() Method:

Syntax:

Output

Reading and Writing Files:

The write() Method:

Syntax:

The read() Method:

Syntax:

File Positions:

Renaming and Deleting Files:

The rename() Method:

Syntax:

Example:

The delete() Method:

Syntax:

Example: