drop values list python code example

Example 1: python list .remove

a = [10, 20, 30, 20]
a.remove(20)
# a = [10, 30, 20]
# removed first instance of argument

Example 2: remove value from python list by value

>>> a = ['a', 'b', 'c', 'd']
>>> a.remove('b')
>>> print a
['a', 'c', 'd']