CSVParseException data encoding_error ai_generated true

CSV parsing error: quote character mismatch — expected '"' but found ''

ID: data/csv-quote-escape-mismatch

Also available as: JSON · Markdown · 中文
90%Fix Rate
88%Confidence
1Evidence
2024-01-20First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
python 3.12 active — — —
pandas 2.2.0 active — — —
apache-commons-csv 1.10.0 active — — —

Root Cause

CSV file uses single quotes for quoting fields but parser expects double quotes, or vice versa, often due to locale or export settings.

generic

中文

CSV文件使用单引号引用字段，但解析器期望双引号，反之亦然，通常由于区域设置或导出设置导致。

Official Documentation

https://pandas.pydata.org/docs/reference/api/pandas.read_csv.html

Workarounds

  1. 90% success Specify the correct quote character in pandas: `pd.read_csv('file.csv', quotechar="'")` if the file uses single quotes. 
    Specify the correct quote character in pandas: `pd.read_csv('file.csv', quotechar="'")` if the file uses single quotes.
  2. 85% success Use the `escapechar` parameter if quotes are escaped with backslash: `pd.read_csv('file.csv', escapechar='\\')`. 
    Use the `escapechar` parameter if quotes are escaped with backslash: `pd.read_csv('file.csv', escapechar='\\')`.
  3. 95% success Preprocess the file with a Python script to normalize quotes: `import csv; with open('input.csv', 'r') as f, open('output.csv', 'w', newline='') as out: reader = csv.reader(f, quotechar="'"); writer = csv.writer(out, quotechar='"'); writer.writerows(reader)` 
    Preprocess the file with a Python script to normalize quotes: `import csv; with open('input.csv', 'r') as f, open('output.csv', 'w', newline='') as out: reader = csv.reader(f, quotechar="'"); writer = csv.writer(out, quotechar='"'); writer.writerows(reader)`

中文步骤

  1. Specify the correct quote character in pandas: `pd.read_csv('file.csv', quotechar="'")` if the file uses single quotes.
  2. Use the `escapechar` parameter if quotes are escaped with backslash: `pd.read_csv('file.csv', escapechar='\\')`.
  3. Preprocess the file with a Python script to normalize quotes: `import csv; with open('input.csv', 'r') as f, open('output.csv', 'w', newline='') as out: reader = csv.reader(f, quotechar="'"); writer = csv.writer(out, quotechar='"'); writer.writerows(reader)`

Dead Ends

Common approaches that don't work:

  1. Manually replacing all single quotes with double quotes in the CSV file using sed 60% fail

    This can corrupt data if single quotes are part of the field content (e.g., names like O'Brien).

  2. Ignoring the error and proceeding with partially parsed data 95% fail

    Results in misaligned columns and corrupt data; downstream processes will fail or produce wrong results.

  3. Specifying quote character in parser but using the wrong escape character 70% fail

    If the escape character is also wrong (e.g., backslash vs doubling), parsing will still fail on embedded quotes.