Let's tackle this error you're hitting when trying to resample a Pandas Series. First, let's recap your code and the error you saw to make sure we're aligned:

Your Code: #

import pandas as pd
index = pd.date_range('1/1/2000', periods=9, freq='T')
series = pd.Series(range(9), index=index)
series.resample('3T').mean()

The Error You Encountered: #

ImportError: cannot import name 'ResamplerWindowApply' from 'pandas.core.apply' (C:\Users\XXX\AppData\Local\Continuum\anaconda3\lib\site-packages\pandas\core\apply.py)

This error almost always comes down to Pandas version incompatibility or a corrupted installation. Here are actionable steps to fix it:

• Upgrade Pandas to the latest stable version
  The ResamplerWindowApply class may have been moved, renamed, or added in newer releases—older versions might not have it. Use the right command for your environment:

  • For pip: pip install --upgrade pandas
  • For Anaconda/conda: conda update pandas

• Reinstall Pandas if upgrading doesn't resolve the issue
  Sometimes installation files get corrupted during updates or initial setup. A fresh install can clear this up:

  • Pip:

    pip uninstall pandas -y
    pip install pandas
    

  • Conda:

    conda remove pandas -y
    conda install pandas
    

• Double-check your active environment
  If you're using Anaconda, it's easy to accidentally work in an environment with an outdated Pandas version. Confirm you're in the right place:

  • Run conda info --envs to list all your environments
  • On Windows, run where python; on Linux/macOS, run which python to verify you're using the Python path linked to your intended environment

After trying these steps, run your resampling code again—it should work as expected!

内容的提问来源于stack exchange，提问作者user292005