Python Essential Reference, Second Edition

Conditionals

The if, else, and elif statements control conditional code execution. The general format of a conditional statement is as follows:

if expression: 
    statements 
elif expression: 
    statements 
elif expression: 

    statements 
... 
else: 
    statements
				

If no action is to be taken, you can omit both the else and elif clauses of a conditional. Use the pass statement if no statements exist for a particular clause:

if expression: 
    pass            # Do nothing 
else: 
    statements