The `isalpha()` function in Python is a string method used to check whether all the characters in a given string are alphabetic (letters only). It returns `True` if all characters in the string are alphabetic and the string is non-empty, otherwise it returns `False`.
Syntax
string.isalpha()
Example
Here’s an example to demonstrate the usage of the `isalpha()` function:
```python # Example 1: All alphabetic characters str1 = "Hello" print(str1.isalpha()) # Output: True # Example 2: Contains non-alphabetic characters str2 = "Hello123" print(str2.isalpha()) # Output: False # Example 3: Contains space str3 = "Hello World" print(str3.isalpha()) # Output: False # Example 4: Empty string str4 = "" print(str4.isalpha()) # Output: False ```
Explanation
Example 1: The string `”Hello”` contains only alphabetic characters, so `isalpha()` returns `True`.
Example 2: The string `”Hello123″` contains numbers along with alphabetic characters, so `isalpha()` returns `False`.
Example 3: The string `”Hello World”` contains a space, which is not an alphabetic character, so `isalpha()` returns `False`.
Example 4: An empty string is checked, and since it contains no characters, `isalpha()` returns `False`.
The `isalpha()` function is useful when you want to ensure that a string contains only letters before performing further operations on it.