TypeError: Expected String or Bytes-Like Object error occurs when we create a function that takes a string or byte object but received something else. This error is common when using user-defined and built-in functions. The simplest way to fix the TypeError: Expected String or Bytes-Like Object error is to pass the correct argument to the function. This short article will discuss how we can solve TypeError: Expected String or Bytes-Like Object errors using various methods. Moreover, we will also cover how to interpret and understand the errors in Python.
TypeError: Expected String or Bytes-Like Object
We we are dealing with functions in Python, either built-in or user-defined ones. We might face TypeError: Expected String or Bytes-Like Object error. The reason for getting this error is that the function expects a string or Byte-like object as an argument and we provide something else.
The easiest way to solve the error is to provide the argument that is either Strings or bytes.
Let us take an example and see how we get TypeError: Expected String or Bytes-Like Object error:
# importing regular expressions
import re
# integer type
variable = 21
# providing integer to function
textonly = re.sub("[^a-zA-Z]", " ",variable)---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
/tmp/ipykernel_243942/1900251177.py in <module>
6
7 # providing integer to function
----> 8 textonly = re.sub("[^a-zA-Z]", " ",variable)
/usr/lib/python3.10/re.py in sub(pattern, repl, string, count, flags)
207 a callable, it's passed the Match object and must return
208 a replacement string to be used."""
--> 209 return _compile(pattern, flags).sub(repl, string, count)
210
211 def subn(pattern, repl, string, count=0, flags=0):
TypeError: expected string or bytes-like objectThe reason for getting this error is that the sub-function expects to have a string or Bytes-like object.
Now, let us solve the issues using possible ways: We will solve the error using the following methods:
- Using str() method
- Providing an empty string
- Using the if statement
- Using try-except block
Let us explain each method in more detail.
Using str() method
We know the error is because the argument type is not string or Bytes. We can solve the issue using str() method which will convert any non-string data type into a string:
# importing regular expressions
import re
# integer type
variable = 21
# providing integer to function
textonly = re.sub("[^a-zA-Z]", " ",str(variable))Notice that we have used the str() method around the variable which converted the integer value into a string.
Provide an empty string
Another method to solve the issue is to provide an empty string when the variable type is None.
For example, let us say the type of the variable is none which gives:
# importing regular expressions
import re
# integer type
variable = None
# providing integer to function
textonly = re.sub("[^a-zA-Z]", " ",variable)---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
/tmp/ipykernel_243942/2948962086.py in <module>
6
7 # providing integer to function
----> 8 textonly = re.sub("[^a-zA-Z]", " ",variable)
/usr/lib/python3.10/re.py in sub(pattern, repl, string, count, flags)
207 a callable, it's passed the Match object and must return
208 a replacement string to be used."""
--> 209 return _compile(pattern, flags).sub(repl, string, count)
210
211 def subn(pattern, repl, string, count=0, flags=0):
TypeError: expected string or bytes-like objectTo solve the problem, which is caused by a None type variable, we need to provide an empty string after the variable as shown below:
# importing regular expressions
import re
# integer type
variable = None
# providing integer to function
textonly = re.sub("[^a-zA-Z]", " ",variable or '')This will help us to get rid of TypeError: expected string or bytes-like object error.
Using the if statement
So far, we have learned how we can solve the expected string or bytes-like object error. Now, we will discuss how we can handle the error so that even if the error occurs the program will not crash.
We can use the if-else statements in order to handle the error. First, we will check if the type of the argument is string or not. If not, then we will print the type of the string as shown below:
# importing regular expressions
import re
# integer type
variable = 23
# if statement
if variable is str:
# providing integer to function
textonly = re.sub("[^a-zA-Z]", " ",variable)
# else statements
else:
print("The data type of argument is:", type(variable))
The data type of argument is: <class 'int'>As you can see, we got the message that shows the type of argument:
Using try-except blocks
The try-except blocks are used to handle errors in Python. The code inside the try block will be executed first and if the error occurs then the except block will be executed:
# importing regular expressions
import re
# integer type
variable = 23
# try block
try:
# providing integer to function
textonly = re.sub("[^a-zA-Z]", " ",variable)
# except block
except:
print("The data type of argument is:", type(variable))
The data type of argument is: <class 'int'>Notice that instead of crashing the code, we handled the error successfully.
Understanding the TypeError: expected string or bytes-like object error
Now let us try to interpret the error. In Python, mostly the errors have two main parts. The first part of the error gives information about the category of the error. For example, in our case, the error belongs to the TypeError category. At the same time, the second part of the error gives more specific information about the error. In our case, the error clearly says that the code excepted to have a string or byte object which means the function was expecting to have a string of byte type argument but we have provided an argument with different data typed:
Summary
In this short article, we discussed how we can solve expected string or bytes-like object errors using various methods. We covered four different methods to solve the error, examples, and explanations. Moreover, we also discussed how to understand errors in Python as well