if a is not an element in a list how to print?
1194
Finding the index of an item in a list
18795
Find the Smallest Integer Not in a List
21229
If an element is not in the set difference $A\setminus B \: \:?$
110685
How can I print a list of elements separated by commas?
35503
Understanding Python's "is" operator
126490
How can I remove B -> A from a list if A -> B is in the list?
47144
Package to test whether a string is in a list
109300
Handle either a list or single integer as an argument
87374
Python: Finding differences between elements of a list
88394
Check if one list contains element from the other
151816
What is the semantics of 'is' operator in Python?
60433
How to count the number of occurrences of an element in a List
20757
How should I compare each element values in two lists?
39443
Remove duplicate rules in a list?
48135
if/else in a list comprehension
98418
Can I write a CSS selector selecting elements NOT having a certain class or attribute?
106983
Python `if x is not None` or `if not x is None`?