Pandas DataFrame mypy error: slice index must be an integer or None
The following line
pd.DataFrame({"col1": [1.1, 2.2]}, index=[3.3, 4.4])[2.5:3.5]
raises a mypy linting error of on the [2.5
Slice index must be an integer or None
This is valid syntax and correctly returns
col1
3.3 1.1
Without # type: ignore
, how can I resolve this linting error?
versions:
- pandas 1.3.0
- mypy 0.931
The code in question:
def get_dataframe(
ts_data: GroupTs,
ts_group_name: str,
start_time: Optional[float] = None,
end_time: Optional[float] = None,
) -> pd.DataFrame:
df = pd.DataFrame(ts_data.group[ts_group_name].ts_dict)[
start_time:end_time
].interpolate(
method="index", limit_area="inside"
) # type: pd.DataFrame
return df[~df.index.duplicated()]
This is by design for now, I fear, but if you have to, you can silence mypy by slicing with a callable, like this:
import pandas as pd
df = pd.DataFrame({"col1": [1.1, 2.2]}, index=[3.3, 4.4])[
lambda x: (2.5 <= x.index) & (x.index < 3.5)
]
print(df)
# Ouput
col1
3.3 1.1
And so mypy reports no issues found
on this code.