Python program to check whether a string contains a number or not

Python isdigit() work example: Here, we will figure out how to check whether a string contains just digits or not for example string contains just number or not?

Given a string and we need to check whether it contains just digits or not in Python.

To watch that a string contains just digits (or a string has a number) – we can utilize isdigit() work, it returns genuine if all characters of the string are digits.

Syntax:

    string.isdigit()

Example:

    Input:
    str1 = "8789"
    str2 = "Hello123"
    str3 = "123Hello"
    str4 = "123 456" #contains space 

    # function call
    str1.isdigit()
    str2.isdigit()
    str3.isdigit()
    str4.isdigit()

    Output:
    True
    False
    False
    False

Python code to check whether a string contains a number or not:

# python program to check whether a string 
# contains only digits or not 

# variables declaration & initializations
str1 = "8789"
str2 = "Hello123"
str3 = "123Hello"
str4 = "123 456"    #contains space 

# checking
print("str1.isdigit(): ", str1.isdigit())
print("str2.isdigit(): ", str2.isdigit())
print("str3.isdigit(): ", str3.isdigit())
print("str4.isdigit(): ", str4.isdigit())

# checking & printing messages
if str1.isdigit():
    print("str1 contains a number")
else:
    print("str1 does not contain a number")

if str2.isdigit():
    print("str2 contains a number")
else:
    print("str2 does not contain a number")

if str3.isdigit():
    print("str3 contains a number")
else:
    print("str3 does not contain a number")

if str4.isdigit():
    print("str4 contains a number")
else:
    print("str4 does not contain a number")

Output:

str1.isdigit():  True
str2.isdigit():  False
str3.isdigit():  False
str4.isdigit():  False
str1 contains a number
str2 does not contain a number
str3 does not contain a number
str4 does not contain a number