python name started with underscore underscore code example

Example 1: how to use underscore in python

>>> def function(class):
  File "<stdin>", line 1
    def function(class):
                 ^
SyntaxError: invalid syntax
>>> def function(class_):
...     pass
...
>>>

Example 2: how to use underscore in python

def public_api():
    print ("public api")
  
def _private_api():
    print ("private api")