Why replace in this code approves float numbers as numeric . I have tried floats without replace and-CodePudding

#user inputs a number
number = input("Enter number: ")
# 1) changes dot and creates a new string,2) verifies is it a number
if(not number.replace(".","").isnumeric()):
    print("Sorry number is not numeric")

Generally replace changes old value with a new one.

CodePudding user response：

isnumeric returns True if and only if every character of the string is a numeric character as defined by Unicode. Periods are not numeric, but many characters that contain or represent numbers, such as ½ or 六, are considered numeric.

First, you probably want isdigit instead, because a lot of the numeric characters in Unicode aren't valid in float numbers. isdigit only returns True if every character is one of the ASCII digits 0-9.

Second, to validate if the input is a float, it's "Better to Ask Forgiveness than Permission": try converting it as a float directly, and see if that fails:

try:
    float(number)
except ValueError:
    print("Sorry number is not a float")

CodePudding user response：

number = input("Enter number: ")
if(not number.replace(".","").isnumeric()):
    print("Sorry number is not numeric")

Replace here change dot, creates a new string and makes isnumeric() to be True for float numbers.