In this tutorial, we will discuss what the
pass
keyword is and when and where we can use it. We will see examples of
pass
keyword and understand how it works.
What is the pass keyword and what it does in python?
Python 3.X versions have 33 keywords and
pass
is one of them. Like comments in python
pass
keyword also do nothing when it executes and that’s what it does, do nothing just pass the interpreter. It is used as a placeholder for the python statements like
if
,
else
,
for
,
elif
,
while
,
functions
,
and
class
.
Let’s take an example to better understand the
pass
keyword.
In python, if you use an
if
,
elif
,
else
, functions, class, for loops, while loops
you need to define their body or block of code corresponding to them, if you don’t the python interpreter will throw an error. So, to overcome this error you can use the
pass
keyword as a body of the corresponding statement and the statement do nothing and throw no error.
Example Let’s understand it with an example:
1. What if we do not use the pass keyword?
number = 10
if number == 9:
else:
print("hello")
#Output
File "importt.py", line 3
else:
^
IndentationError: expected an indented block
Behind the code
In the above example, you can see that we have not declared the body of
if
statement, and when the python interpreter reaches at the
if
statement it did not find any code for
if
block, even though its expression was wrong, it did not goanna run in either way but it should have a body. At the moment the interpreter finds that the
if
statement does not have a body corresponding to it the interpreter threw an error.
2. Using the pass
number = 10
if number == 9:
pass
else:
print("hello")
#Output
hello