copy() missing 1 required positional argument:

from openpyxl import load_workbook, Workbook
import os
from openpyxl.styles import Font, colors, Alignment, Border, Side, Color, Fill

main_data = {}

for file in os.listdir('maindata'):
    # print(file)
    wb = load_workbook(os.path.join('maindata', file))
    ws = wb.worksheets[0]
    temp = []
    for r in list(ws.iter_rows())[1:]:
        row = [data.value for data in r]  # 一行数一个list
        temp.append(row)
        main_data[file.split('.')[0]] = temp

print(main_data)

这是我用教程上做好的代码原封不动运行，然后出现了以下错误：

Traceback (most recent call last):
  File "C:/Users/dell/Desktop/第4讲源码：课堂练习-三剑客/excel_task/excel_main.py", line 1, in <module>
    from openpyxl import load_workbook, Workbook
  File "C:\ProgramData\Anaconda3\lib\site-packages\openpyxl\__init__.py", line 4, in <module>
    from openpyxl.compat.numbers import NUMPY, PANDAS
  File "C:\ProgramData\Anaconda3\lib\site-packages\openpyxl\compat\__init__.py", line 3, in <module>
    from .numbers import NUMERIC_TYPES
  File "C:\ProgramData\Anaconda3\lib\site-packages\openpyxl\compat\numbers.py", line 48, in <module>
    import pandas
  File "C:\ProgramData\Anaconda3\lib\site-packages\pandas\__init__.py", line 142, in <module>
    from pandas.io.api import (
  File "C:\ProgramData\Anaconda3\lib\site-packages\pandas\io\api.py", line 16, in <module>
    from pandas.io.pickle import read_pickle, to_pickle
  File "C:\ProgramData\Anaconda3\lib\site-packages\pandas\io\pickle.py", line 7, in <module>
    from pandas.compat import pickle_compat as pc
  File "C:\ProgramData\Anaconda3\lib\site-packages\pandas\compat\pickle_compat.py", line 192, in <module>
    Unpickler.dispatch = copy.copy(Unpickler.dispatch)
TypeError: copy() missing 1 required positional argument: 'dst'

进程已结束，退出代码为 1

有人知道是为什么吗？