[python] python: changing row index of pandas data frame

I have a data frame called followers_df as below:

 followers_df

             0
0         oasikhia 
0     LEANEnergyUS
0  _johannesngwako
0     jamesbreenre
0   CaitlinFecteau
0  mantequillaFACE
0         apowersb
0       ecoprinter
0        tsdesigns
0      GreenBizDoc
0        JimHarris
0    Jmarti11Julia
0         JAslat63
0            prAna
0    GrantLundberg 
0        Jitasa_Is
0     ChoosePAWind
0  cleanpowerperks
0          WoWEorg
0      Laura_Chuck

I want to change this data frame into something like this:

 followers_df

             0
0          oasikhia 
1      LEANEnergyUS
2   _johannesngwako
3      jamesbreenre
4    CaitlinFecteau
5   mantequillaFACE
6          apowersb
7        ecoprinter
8         tsdesigns
9       GreenBizDoc
10        JimHarris
11    Jmarti11Julia
12         JAslat63
13            prAna
14    GrantLundberg 
15        Jitasa_Is
16     ChoosePAWind
17  cleanpowerperks
18          WoWEorg
19      Laura_Chuck

how can I do this? I tried:

     index = pandas.Index(range(20))
     followers_df = pandas.DataFrame(followers_df, index=index)

but it's giving me the following error:

  ValueError: Shape of passed values is (1, 39), indices imply (1, 20)

thanks,

When you are not sure of the number of rows, then you can do it this way:

followers_df.index = range(len(followers_df))

followers_df.reset_index()
followers_df.reindex(index=range(0,20))