Insert an empty row at a specific index and shift its values down dataframe

Question

so for example I have this dataframe:

	onset	length
1	2.215	1.3
2	23.107	1.3
3	41.815	1.3
4	61.606	1.3
5	Nan	Nan

and want to change it to this :

	onset	length
1	2.215	1.3
2	Nan	Nan
3	23.107	1.3
4	41.815	1.3
5	61.606	1.3

Answer 1

You can stack appends if necessary.

i = 2 # your target index

head = df[:i]
tail = df[i:]

inserted = pd.DataFrame([[np.nan] * len(df.columns)], columns=df.columns)

result = head.append(inserted, ignore_index=True)
result = result.append(tail, ignore_index=True)

print(result)