Python读取JSON文件遇UnicodeDecodeError：原因及解决方法

Let’s break down what’s causing this error and how to fix it step by step.

Why This Error Happens #

The error you’re hitting boils down to an encoding mismatch. When you open a file without specifying an encoding, Python defaults to using your system’s native encoding—here, that’s cp1252, a Windows-specific character set. But your StreamingHistory0.json file is almost certainly saved in UTF-8 (the standard encoding for JSON files), which includes characters that cp1252 doesn’t recognize (like the 0x81 byte mentioned in the error). Python tries to decode the file with cp1252, hits a character it can’t map to a readable symbol, and throws that UnicodeDecodeError.

Fixes to Try #

1. Specify UTF-8 Encoding (Recommended) #

Since UTF-8 is the universal standard for JSON, this is the most reliable fix. Just add the encoding='utf-8' parameter to your open() call:

import json
with open('StreamingHistory0.json', encoding='utf-8') as json_file:
    history = json.load(json_file)

This tells Python to use the correct encoding to decode all Unicode characters in your streaming history file.

2. Ignore Unreadable Characters (Last Resort) #

If you need a quick workaround and don’t mind losing a tiny bit of data, you can tell Python to skip characters it can’t decode with the errors='ignore' parameter. Note: This will discard the unreadable characters, so use this only if you don’t care about that specific data:

import json
with open('StreamingHistory0.json', errors='ignore') as json_file:
    history = json.load(json_file)

3. Detect the File’s Exact Encoding #

If you’re unsure what encoding your file uses, use the chardet library to detect it automatically. First, install the library:

pip install chardet

Then run this code to get the encoding:

import chardet

with open('StreamingHistory0.json', 'rb') as f:
    encoding_result = chardet.detect(f.read())

print(f"Detected encoding: {encoding_result['encoding']}")

Once you have the detected encoding, plug it into your open() call (e.g., encoding='utf-16' if that’s what shows up).

内容的提问来源于stack exchange，提问作者Shubham Kalantri