pandas set index integer not float
df["int"] = pd.Series([], dtype=object)
df["str"] = pd.Series([], dtype=str)
df.loc[0] = [0, "zero"]
print(df)
print()
df.loc[1] = [1, None]
print(df)
int str
0 0 zero
1 NaN NaN
int str
0 0 zero
1 1 None