python - 空数据错误 : No columns to parse from file about streamlit

Question

我使用的是 streamlit 版本 v0.68，目前正在处理 CSV 文件以进行数据分析。

st.title('Report Analysis')
uploaded_file = st.file_uploader("Choose a file")
if uploaded_file is not None:
    data = pd.read_csv(uploaded_file, low_memory=False)
    st.write(data.shape)

首先它可以工作，但是如果我在本地主机中重新运行该程序，则会出现错误:

EmptyDataError: No columns to parse from file
Traceback:

File "D:\My Programs\Projects\ReportAnalysis\venv\lib\site-packages\streamlit\script_runner.py", line 324, in _run_script
    exec(code, module.__dict__)
File "D:\My Programs\Projects\ReportAnalysis\epl\app.py", line 9, in <module>
    data = pd.read_csv(uploaded_file, low_memory=False)
File "D:\My Programs\Projects\ReportAnalysis\venv\lib\site-packages\pandas\io\parsers.py", line 686, in read_csv
    return _read(filepath_or_buffer, kwds)
File "D:\My Programs\Projects\ReportAnalysis\venv\lib\site-packages\pandas\io\parsers.py", line 452, in _read
    parser = TextFileReader(fp_or_buf, **kwds)
File "D:\My Programs\Projects\ReportAnalysis\venv\lib\site-packages\pandas\io\parsers.py", line 946, in __init__
    self._make_engine(self.engine)
File "D:\My Programs\Projects\ReportAnalysis\venv\lib\site-packages\pandas\io\parsers.py", line 1178, in _make_engine
    self._engine = CParserWrapper(self.f, **self.options)
File "D:\My Programs\Projects\ReportAnalysis\venv\lib\site-packages\pandas\io\parsers.py", line 2008, in __init__
    self._reader = parsers.TextReader(src, **kwds)
File "pandas\_libs\parsers.pyx", line 540, in pandas._libs.parsers.TextReader.__cinit__

如何处理这个错误？

Answer 1

根据 this post from the Streamlit community page ，这是因为它们在应用程序第二次刷新时返回相同的缓冲区。由于 pd.read_csv 耗尽了缓冲区，您第二次调用 read_csv 将不会返回任何行。
添加 seek(0)重置缓冲区对我有用。
例如

st.title('Report Analysis')
uploaded_file = st.file_uploader("Choose a file")
if uploaded_file is not None:
    uploaded_file.seek(0)
    data = pd.read_csv(uploaded_file, low_memory=False)
    st.write(data.shape)