ExcelWriter mode error

[cameronb-ma]

Describe the bug
"a" should be allowed for mode argument of ExcelWriter

To Reproduce

import pandas as pd

df = pd.DataFrame([["ABC", "XYZ"]], columns=["Foo", "Bar"])
with pd.ExcelWriter("path_to_file.xlsx", mode="a", engine="openpyxl") as writer:
    df.to_excel(writer, sheet_name="Example_Sheet")

mypy reports

Argument "mode" to "ExcelWriter" has incompatible type "Literal['a']"; expected "Union[Literal['w'], Literal['writer']]"

Please complete the following information:

• OS: MacOS Monterey 12.6
• python version 3.9.10
• mypy version 0.931
• pandas version 1.5.0
• pandas-stubs version 1.5.0.221003

[bashtage]

Thanks. Want to submit a PR? Also not clear why writer is allowed.

…

On Wed, Oct 5, 2022, 10:09 Cameron Barker ***@***.***> wrote: *Describe the bug* "a" should be allowed for mode argument of ExcelWriter *To Reproduce* import pandas as pd df = pd.DataFrame([["ABC", "XYZ"]], columns=["Foo", "Bar"])with pd.ExcelWriter("path_to_file.xlsx", mode="a", engine="openpyxl") as writer: df.to_excel(writer, sheet_name="Example_Sheet") mypy reports Argument "mode" to "ExcelWriter" has incompatible type "Literal['a']"; expected "Union[Literal['w'], Literal['writer']]" *Please complete the following information:* - OS: MacOS Monterey 12.6 - python version 3.9.10 - mypy version 0.931 - pandas version 1.5.0 - pandas-stubs version 1.5.0.221003 — Reply to this email directly, view it on GitHub <#356>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABKTSRIZCD74VOL2DRG7KU3WBVATZANCNFSM6AAAAAAQ5MHH5Q> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>