How to fill in rows with repeating data in pandas?

Question

In R, when adding new data of unequal length to a data frame, the values repeat to fill the data frame:

df <- data.frame(first=c(1,2,3,4,5,6))
df$second &         


        

Answer 1

Seems there is no elegant way. This is the workaround I just figured out. Basically create a repeating list just bigger than original dataframe, and then left join them.

import pandas
df = pandas.DataFrame(range(100), columns=['first'])
repeat_arr = [1, 2, 3]
df = df.join(pandas.DataFrame(repeat_arr * (len(df)/len(repeat_arr)+1),
    columns=['second']))