pandas add row and index code example

Example 1: add rows to dataframe pandas

df = df.append({'a':1, 'b':2}, ignore_index=True)

Example 2: insert row in any position pandas dataframe

line = DataFrame({"onset": 30.0, "length": 1.3}, index=[3])
df2 = concat([df.iloc[:2], line, df.iloc[2:]]).reset_index(drop=True)