One error you may encounter when using Python is:
TypeError: expected string or bytes-like object
This error typically occurs when you attempt to use the re.sub() function to replace certain patterns in an object but the object you’re working with is not composed entirely of strings.
The following example shows how to fix this error in practice.
How to Reproduce the Error
Suppose we have the following list of values:
#define list of values x = [1, 'A', 2, 'B', 5, 'C', 'D', 'E']
Now suppose we attempt to replace each non-letter in the list with an empty string:
import re #attempt to replace each non-letter with empty string x = re.sub('[^a-zA-Z]', '', x) TypeError: expected string or bytes-like object
We receive an error because there are certain values in the list that are not strings.
How to Fix the Error
The easiest way to fix this error is to convert the list to a string object by wrapping it in the str() operator:
import re #replace each non-letter with empty string x = re.sub('[^a-zA-Z]', '', str(x)) #display results print(x) ABCDE
Notice that we don’t receive an error because we used str() to first convert the list to a string object.
The result is the original list with each non-letter replaced with a blank.
Note: You can find the complete documentation for the re.sub() function here.
The following tutorials explain how to fix other common errors in Python: