Python
In this tutorial we will learn about Python syntax.
We create single line comments in Python using the hash # symbol.
#
In the following example we are creating a single line comment.
# hello world this is a single line comment...
For multiline comments we use delimiter """ at the start and end of the comment.
"""
In the following example we are creating a multiline comment.
""" Hello World This is a multiple line comment... """
;
If you are familiar with other programming languages like C and Java then you know that we have to end the line with the semicolon ; character.
In Python we don't have to end the line with semicolon. You can put a semicolon if you want but it is not required.
Python is case-sensitive language. This means a variable named score is completely different from a variable named SCORE.
score
SCORE
We use indentations in other programming languages to make the code more readable.
In Python, indentations holds a special meaning. It defines a block of code.
For example, we will write the following to create a if-statement in PHP.
// set value of x $x = 1; // now check if ($x == 1) { echo "x is 1"; } else { echo "x is not 1"; }
In Python we don't have to use the curly-brackets { } but instead we use indentation to make the if and else block.
{ }
if
else
# set value of x x = 1 # now check if x == 1: print("x is 1") else: print("x is not 1")
Indentation in Python indicates a block of code. So, each line in a block must be indented the same amount.
Following code will give error as third line in the if-block is not properly indented.
x = 1 if x == 1: print("x is 1") print("x is an integer") print("This line will give us error") # this line is not correctly indented
If we run the above code we will get a similar error output.
File "/Users/yusufshakeel/PycharmProjects/HelloWorld/Syntax.py", line 5 print("This line will give us error") # this line is not correctly indented ^ IndentationError: unexpected indent
In Python we can use single quote ', double quotes " and triple quotes ''' to denote string literal.
'
"
'''
In the following example we are assigning string value to a variable using single quote.
msg = 'Hello World'
In the following example we are assigning string value to a variable using double quotes.
msg = "Hello World"
In the following example we are assigning multiline string value to a variable using triple quotes.
msg = '''Hello World This is a multiline string value'''
We can also mix the quotes. In the following example we are using double quotes inside single quotes.
msg = 'This is the "Hello World" message.'
The above code will give us the following output.
This is the "Hello World" message.