How to convert index of a pandas dataframe into a column?

Question

This seems rather obvious, but I can\'t seem to figure out how to convert an index of data frame to a column?

For example:

df=
        gi       ptt_l         


        

Answer 1

df1 = pd.DataFrame({"gi":[232,66,34,43],"ptt":[342,56,662,123]})
p = df1.index.values
df1.insert( 0, column="new",value = p)
df1

    new     gi     ptt
0    0      232    342
1    1      66     56 
2    2      34     662
3    3      43     123