Finding Items in Lists with the in Operator

The in operator is used in Python to determine whether an item is contained in a list.

Here is the general format of an expression written with the in operator to search for an item in a list:

 item in list

In the general format, item is the item for which you are searching, and list is a list. The expression returns true if item is found in the list or false otherwise.

# This program demonstrates the in operator used with a list.

def main():

# Create a list of product numbers.

prod_nums = ['V400', 'F900', 'Q143', 'R600']

# Get a product number to search for.

search = input('Enter a product number: ')

# Determine whether the product number is in the list.

if search in prod_nums:

print(search, 'was found in the list.')

else:

print(search, 'was not found in the list.')

# Call the main function.

main()