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Python in Keyword

By IncludeHelp Last updated : December 07, 2024

Description and Usage

The in is a keyword (case-sensitive) in python, it is used to check whether an element exists in the given sequence like string, list, tuple, etc.

The in keyword is also used with the for loop to iterate the sequence.

Syntax

Syntax of in keyword:

if element in sequence:
  statement(s)

for element in sequence:
  statement(s)

Sample Input/Output

Input:
cities = ["New Delhi", "Mumbai", "Chennai", "Banglore"]

# condition
if "Mumbai" in cities:
  print("Yes")
else:
  print("No")

Output:
Yes

Example 1

Check whether an element exits in a list of not.

# python code to demonstrate example of 
# in keyword

# Check whether an element exits in a list of not

# create a list
cities = ["New Delhi", "Mumbai", "Chennai", "Banglore"]

# check if "Mumbai" is present in the list or not
if "Mumbai" in cities:
    print("Yes \"Mumbai\" exists in the list")
else:
    print("No \"Mumbai\" does not exist in the list")

# now check...
# "Gwalior" is present in the list or not
if "Gwalior" in cities:
    print("Yes \"Gwalior\" exists in the list")
else:
    print("No \"Gwalior\" does not exist in the list")

Output

Yes "Mumbai" exists in the list
No "Gwalior" does not exist in the list

Example 2

Take a string and print the characters one by one until a dot (".") is not found.

# python code to demonstrate example of 
# in keyword

# Take a string and print the characters one by one 
# until a dot ('.') is not found.

# string input
string = input("Enter a string: ")

# print characters until dot is not found
for ch in string:
    if ch=='.':
        break
    print(ch)

Output

Enter a string: IncludeHelp.com
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