python runtime_error ai_generated true

ValueError: No objects to concatenate

ID: python/pandas-concat-empty-frames

Also available as: JSON · Markdown · 中文
80%Fix Rate
88%Confidence
0Evidence
2024-03-30First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
3.x active — — —

Root Cause

pd.concat() received an empty list, typically because a filter or list comprehension produced no DataFrames.

generic

中文

pd.concat() 收到空列表，通常因为过滤或列表推导未产生任何 DataFrame。

Workarounds

  1. 95% success 
    if frames: result = pd.concat(frames, ignore_index=True) else: result = pd.DataFrame()
  2. 90% success 
    result = pd.concat(frames or [pd.DataFrame()], ignore_index=True)

Dead Ends

Common approaches that don't work:

  1. 90% fail

    ignore_index doesn't help with empty list

  2. 75% fail

    Downstream code then fails on None