Implement isnumber Function in Python

In this article, we will about the implement isNumber() method using Python 3.x. Or earlier.

This method takes in a string type as input and returns boolean True or False according to whether the entered string is a number or not. To do this we take the help of exception handling by using try and except statement.

Example

Let’s look at some example −

 Live Demo

# Implementation of isNumber() function
def isNumber(s):
   if(s[0] =='-'):
      s=s[1:]
   #exception handling
   try:
      n = int(s)
      return True
   # catch exception if any error is encountered
   except ValueError:
      return False
inp1 = "786"
inp2 = "-786"
inp3 = "Tutorialspoint"
print(isNumber(inp1))
print(isNumber(inp2))
print(isNumber(inp3))

Output

True
True
False

Conclusion

In this article, we learnt how to implement Implement IsNumber() function in Python 3.x. Or earlier.