typeerror 'nonetype' object is not subscriptable dropna code example

Example: AttributeError: 'NoneType' object has no attribute 'dropna'

import pandas as pd
file = pd.read_csv("/my/path/to/spreadsheet.csv", index_col=0)
file.dropna(how="any", inplace=True)
file = file.fillna("", inplace=False)
print(file)