使用Python open函数读取PNG图片时遇UnicodeDecodeError错误求助

Hey there! That error pops up because you're trying to read a PNG file as if it were plain text—and PNGs are binary files, not text files. Let me break this down and show you how to fix it.

The Root Problem #

When you use open('here.png') without specifying a mode, Python defaults to text mode ('r'). In text mode, it tries to decode the file's bytes into a string using your system's default character codec. But PNG files have binary data that doesn't map to valid text characters, so you get that UnicodeDecodeError.

The Quick Fix #

You need to open the file in binary read mode instead. Just add 'rb' as the second argument to open():

img = open('here.png', 'rb').read()

This tells Python to read the raw bytes of the file without trying to decode them into text—perfect for images, videos, zip files, and other non-text formats.

Bonus: Working with the Image Directly #

If you're planning to manipulate the image (crop, resize, edit pixels, etc.), using the open() function to read bytes is a bit low-level. The Pillow library (a popular image processing tool for Python) makes this way easier:

from PIL import Image

# Open the image directly for editing
img = Image.open('here.png')
# Example: Show the image
img.show()

Just make sure you install Pillow first with pip install pillow if you haven't already.

内容的提问来源于stack exchange，提问作者WhatAMesh