Python String isdigit() function checks for the Digit characters in a string and returns True if the string consists of only digit characters.
Key Points:
- Return Type:Â Boolean i.e. True or False
- Parametric Values:Â No parameters need to be parsed in isdigit() function
- Blank spaces in between digits lead to return False
- Empty String also returns False
String isdigit() Syntax
str_name.isdigit()
str_name here refers to the input string. And, isdigit() is inbuilt string function in python.
str_name = "12345"
print(str_name.isdigit()) # True
String isdigit() Examples
Different cases are given below.
Case 1: String contains whitespaces
str_name = "12 34"
print(str_name.isdigit()) # False
Case 2: String contains alphabets
str_name = "Abc123"
print(str_name.isdigit()) # False
str_name = "Abc"
print(str_name.isdigit()) # False
Case 3: String contains special characters
str_name = "@123"
print(str_name.isdigit()) # False
str_name = "@$&"
print(str_name.isdigit()) # False
Case 4: String contains decimals
str_name = "16.7"
print(str_name.isdigit()) # False
Case 5: String is empty
str_name = ' '
print(str_name.isdigit()) # False
Program to Print List of All Possible Digit Characters in Python
The Unicode module can be used to check the digit characters. The program is to print all digit Unicode characters.
import unicodedata
total_count = 0
for i in range(2 ** 16):
charac = chr(i)
if charac.isdigit():
print(u'{:04x}: {} ({})'.format(i, charac, unicodedata.name(charac, 'UNNAMED')))
total_count = total_count + 1
print("Total Count of Unicode Digit Characters = ",total_count)

It is just a glance of output as the actual output is lengthy. There are 445 digit characters in Unicode.
References
- Python String isdigit()
- Python Built-in String Functions