In programming, a keyword is a “reserved word” by the language that conveys special meaning to the interpreter. It may be a command or a parameter. Keywords cannot be used as a variable name in the program snippet. Python language also reserves some of the keywords that convey special meaning. In Python, keywords are case-sensitive.
Python in Keyword
The ‘in’ keyword in Python returns True if a certain element is present in a Python object, else it will return False. It has two purposes:
- To check if a value is present in a list, tuple, range, string, etc.
- To iterate through a sequence in a for loop.
Python ‘in’ keyword in Expression
The in keyword in Python can be used with if statements as well as with for loops. It has the following syntax:
# Using if statement
if element in sequence:
# statement
# Using for statement
for element in sequence:
# statement
Python in Keyword Usage
Let us see a few examples to know how the “in” keyword works in Python.
“in” Keyword with Python if Statement
In this example, we will create a Python list of animals. Then we will use the in keyword with the if statement to check the presence of “lion” in animals.
Python3
# Python program to demonstrate # in keyword # Create a list animals = ["dog", "lion", "cat"] # Check if lion in list or not if "lion" in animals: print("Yes") |
Output:
Yes
Use of in keyword in for loop in Python
In this example, we will first define a Python String, and use for loop to iterate over each character in that string.
Python3
# Python program to demonstrate # in keyword # Create a string s = "Lazyroar" # Iterating through the string for i in s: # if f occurs in the string # break the loop if i == 'f': break print(i) |
Output:
G
e
e
k
s
