Expected str, bytes or os.PathLike object, not TextIOWrapper

When working with files in Python, it’s common to encounter the “TypeError: expected str, bytes or os.PathLike object, not TextIOWrapper” error. This error occurs when we pass a file object instead of a string to the built-in open() function. In this post, we will explain what causes this error and how to solve it.

Understanding the Error

Here is an example of how the error occurs:

with open('example.txt', 'r', encoding='utf-8') as file1:
    lines = file1.readlines()
    print(lines)
# TypeError: expected str, bytes or os.PathLike object, not TextIOWrapper
with open(file1, 'r', encoding='utf-8') as file2:
    lines = file2.readlines()
    print(lines)

In the above code, the first with open() call is correct as it passes a string (the file name) to the function. However, in the second call, we pass the file1 object, which is a file object returned by the open() function in the previous line.

The open() function expects the first argument to be a string that represents the file name, not a file object. That’s why we get the “TypeError: expected str, bytes or os.PathLike object, not TextIOWrapper” error.

Solving the Error

The solution to this error is simple – pass a string that represents the file name to the open() function.

[Fixed]: Replace spaces with underscores in Python

Here is an example:

with open('example.txt', 'r', encoding='utf-8') as file1:
    lines = file1.readlines()

    print(lines)

with open('example-2.txt', 'r', encoding='utf-8') as file2:
    lines = file2.readlines()
    print(lines)

In this example, we pass two different strings (the file names) to the open() function in the two calls. This will not result in any errors.

Advanced Use Case

If you need to construct the filename by concatenating strings, use a formatted string literal.

name = 'example'
ext = 'txt'

filename = f'{name}.{ext}'

with open(filename, 'r', encoding='utf-8') as f:
    lines = f.readlines()

    for line in lines:
        print(line)

Formatted string literals (f-strings) let us include expressions inside of a string by prefixing the string with f. Make sure to wrap expressions in curly braces – {expression}.

os.pathlike object python example

import os
file_path = os.path.abspath('example.txt')
with open(file_path, 'r', encoding='utf-8') as file:
  lines = file.readlines()
  print(lines)

Conclusion on Expected str, bytes or os.PathLike object, not TextIOWrapper

The “Type Error: expected str, bytes or os.PathLike object, not TextIOWrapper” is a common error that occurs when a file object is passed to the open() function instead of a string. To avoid this error, always make sure to pass the filename as a string to the open() function.

Additionally, when constructing filenames by concatenating strings, it is recommended to use formatted string literals (f-strings) to ensure proper formatting and prevent any errors.

In this blog post, we have discussed the cause of the error and provided examples of how to solve it. We also provided an example of using formatted string literals to construct filenames. By following these guidelines, you can avoid the “TypeError: expected str, bytes or os.PathLike object, not TextIOWrapper” error and ensure that your code runs smoothly.

As a bonus, we have also provided an example of os.pathlike object python in the above example which is a great way to handle file and folder paths in a cross-platform manner. With this, you can easily handle file operations in your Python code.

In summary, always pass the filename as a string to the open() function and use formatted string literals to construct filenames. And make sure to use the os.pathlike object when handling file and folder paths in your Python code.