Adding row to df with df.loc[len(df.index)]

[Mark17]

You are correct about iloc() and loc(). You are confused thinking that "len(df.index)" in "df.loc[len(df.index)] = a" is an integer index. It is a label. It just happens to also be an integer.

This helps. Thanks.

I think what's confusing is that the basic examples I've seen given for .loc[] and .iloc[] will show have string labels for the former and integers for the latter. Here, 42 is a label that also happens to be an integer--like you say. At some point, though, I'd be inclined to ask "what's the difference?" For example, if L6 is:

df.loc[5] = ("Meaning", "Everything")

Evidently, it's not the case that labels can't be integers. It is the case that arguments for .loc[] must be labels--and that is all. If the index is numeric then numeric labels are fine. If the index is string then string labels it must be. Is that accurate?