Python Syntax

Python program is written in a text file editor and save it with .py extension. Invoking the Python interpreter without passing a program file as a parameter brings up the following prompt −

$ python

Python 2.4.3 (#1, Nov 11 2010, 13:34:43)
[GCC 4.1.2 20080704 (Red Hat 4.1.2-48)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>>

Command print the text in python prompt

>>> print ("Hello, Python!")

#Output
Hello, Python!

Another Example

>>> x = 5 >>> print("The Value of x is :", x)

#Output 
The Value of x is : 5

Python Script

Let’s write a Python program in the script. Create the text file in your current working directory and write the following line and save the file with .py extension like test.py. Type the following source code in a test.py file.

print("Hello, Python!")
print("Hello, World!")

To execute the python script, open the command prompt and type python or python3, followed by the name of the script file such as follows:

$ python test.py

#Output
Hello, Python!
Hello, World!

Note:

If you have python version 2.x, use python test.py for execution

If you have python version 3.x, use python3 test.py for execution

Indentation

Unlike the other programming language, Python has no { } to indicate the block of code for functions and class. Python use indentation to indicate a block of code. Indentation refers to the spaces at the beginning of a code line. If indentation is not used it is certain that we get error.

Example:

if 5>3:
    print("5 is greater than 3")

if 5>3:
print("5 is greater than 3")

File "<ipython-input-7-dddc46867ca5>", line 2
    print("5 is greater than 3")
        ^
IndentationError: expected an indented block

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