熊猫DataFrame.to_csv给出无效的切片错误

Question

I am a little baffled as to what is causing this error. A very simple example:

import pandas
df = pandas.DataFrame({"var1" : [1], "var2": [5]})
df.to_csv("csv_file.csv")

gives me the following:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3/dist-packages/pandas/core/frame.py", line 1136, in to_csv
    formatter.save()
  File "/usr/lib/python3/dist-packages/pandas/core/format.py", line 1171, in save
    self._save()
  File "/usr/lib/python3/dist-packages/pandas/core/format.py", line 1277, in _save
    self._save_chunk(start_i, end_i)
  File "/usr/lib/python3/dist-packages/pandas/core/format.py", line 1289, in _save_chunk
    date_format=self.date_format)
  File "/usr/lib/python3/dist-packages/pandas/core/internals.py", line 552, in to_native_types
    values = values[:, slicer]
IndexError: invalid slice

Anyone else encountered this error before?

Answer 1

You have a typo in the definition of df. Use the following:

df = pandas.DataFrame({"var1" : [1], "var2": [5]})

You need : instead of , for var2 .