Is string an alphanumeric python?

Question

❮ String Methods

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Definition and Usage
Parameter Values
More Examples
Python string isalnum() example
Printing all Alphanumeric characters in Python
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Python String isalnum() Method Syntax:
Python String isalnum() Method Example:
Example 1: More examples on Python String isalnum() Method
Example 2: isalnum() in if…else Statement
What is considered alphanumeric in Python?
Are strings alphanumeric?
Is string an alphabet Python?
How do I check if a string contains alphanumeric characters?

Example

Check if all the characters in the text are alphanumeric:

txt = "Company12"

x = txt.isalnum()

print(x)

Try it Yourself »

Definition and Usage

The isalnum() method returns True if all the characters are alphanumeric, meaning alphabet letter (a-z) and numbers (0-9).

Example of characters that are not alphanumeric: (space)!#%&? etc.

Syntax

Parameter Values

No parameters.

More Examples

Example

Check if all the characters in the text is alphanumeric:

txt = "Company 12"

x = txt.isalnum()

print(x)

Try it Yourself »

❮ String Methods

Python string isalnum() function returns True if it’s made of alphanumeric characters only. A character is alphanumeric if it’s either an alpha or a number. If the string is empty, then isalnum() returns False.

Python string isalnum() example

s = 'HelloWorld2019'
print(s.isalnum())

Output: True

s = 'Hello World 2019'

print(s.isalnum())

Output: False because whitespace is not an alphanumeric character.

s = ''
print(s.isalnum())

Output: False because it’s an empty string.

s='A.B'
print(s.isalnum())

s = '10.50'
print(s.isalnum())

Output:

False
False

The string contains period (.) which is not an alphanumeric character.

s = 'çåøÉ'
print(s.isalnum())

Output: True because all these are Alpha characters. Alphabetic characters are those characters defined in the Unicode character database as “Letter”, i.e., those with general category property being one of “Lm”, “Lt”, “Lu”, “Ll”, or “Lo”.

Printing all Alphanumeric characters in Python

We can use unicode module to check if a character is alphanumeric or not. Here is the program to print all the alphanumeric unicode characters.

import unicodedata

count = 0
for codepoint in range(2 ** 16):
    ch = chr(codepoint)
    if ch.isalnum():
        print(u'{:04x}: {} ({})'.format(codepoint, ch, unicodedata.name(ch, 'UNNAMED')))
        count = count + 1
print(f'Total Number of Alphanumeric Unicode Characters = {count}')

Output:

...
ffd7: ￗ (HALFWIDTH HANGUL LETTER YU)
ffda: ￚ (HALFWIDTH HANGUL LETTER EU)
ffdb: ￛ (HALFWIDTH HANGUL LETTER YI)
ffdc: ￜ (HALFWIDTH HANGUL LETTER I)
Total Number of Alphanumeric Unicode Characters = 49567

I have provided only partial output because the number of alphanumeric unicode characters is huge.

You can checkout more Python examples from our GitHub Repository.

Reference: Official Documentation

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Python String isalnum() method checks whether all the characters in a given string are either alphabet or numeric (alphanumeric) characters.

Python String isalnum() Method Syntax:

Syntax: string_name.isalnum()
Parameter: isalnum() method takes no parameters
Return:
True: If all the characters are alphanumeric
False: If one or more characters are not alphanumeric

Python String isalnum() Method Example:

Python program to demonstrate the use of String isalnum() method

Python

string = "abc123"

print(string.isalnum())

Output:

True

Example 1: More examples on Python String isalnum() Method

Python3

string = "abc 123"

print(string, "is alphanumeric?", string.isalnum())

string = "abc_123"

print(string, "is alphanumeric?", string.isalnum())

string = "000"

print(string, "is alphanumeric?", string.isalnum())

string = "aaaa"

print(string, "is alphanumeric?", string.isalnum())

Output:

abc 123 is alphanumeric? False
abc_123 is alphanumeric? False
000 is alphanumeric? True
aaaa is alphanumeric? True

Example 2: isalnum() in if…else Statement

We can also use Python String isalnum() Method along with if…else statements, to output custom messages

Python3

password = "user123456"

if password.isalnum():

print("Password is alphanumeric.")

else:

print("Password is not alphanumeric.")

Output:

Password is alphanumeric.

What is considered alphanumeric in Python?

A character is alphanumeric if it's either an alpha or a number. If the string is empty, then isalnum() returns False .

Are strings alphanumeric?

An alphanumeric string is a string that contains only alphabets from a-z, A-Z and some numbers from 0-9. Explanation: This string contains all the alphabets from a-z, A-Z, and the number from 0-9. Therefore, it is an alphanumeric string.

Is string an alphabet Python?

Python String isalpha() The isalpha() method returns True if all characters in the string are alphabets. If not, it returns False.

How do I check if a string contains alphanumeric characters?

Using Regular Expression The idea is to use the regular expression ^[a-zA-Z0-9]*$ , which checks the string for alphanumeric characters. This can be done using the matches() method of the String class, which tells whether this string matches the given regular expression.

programming python Are strings alphanumeric? Isalnum Python Isdigit Python Isnumeric Python Lower Python Isalpha Python Lowercase Python

Is string an alphanumeric python?

Example

Definition and Usage

Syntax

Parameter Values

More Examples

Example

Python string isalnum() example

Printing all Alphanumeric characters in Python

Want to learn more? Join the DigitalOcean Community!

Python String isalnum() Method Syntax:

Python String isalnum() Method Example:

Python

Example 1: More examples on Python String isalnum() Method

Python3

Example 2: isalnum() in if…else Statement

Python3

What is considered alphanumeric in Python?

Are strings alphanumeric?

Is string an alphabet Python?

How do I check if a string contains alphanumeric characters?

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