Question

The R function rep() replicates each element of a vector:

> rep(c("A","B"), times=2)
[1] "A" "B" "A" "B"

This is like the list multiplication in Python:

>>> ["A","B"]*2
['A', 'B', 'A', 'B']

But with the rep() R function it is also possible to specifiy the number of repeats for each element of the vector:

> rep(c("A","B"), times=c(2,3))
[1] "A" "A" "B" "B" "B"

Is there such a function availbale in Python ? Otherwise how could one define it ? By the way I’m also interested in such a function for duplicating rows of an array.

Answer 1

Use numpy arrays and the numpy.repeat function:

import numpy as np

x = np.array(["A", "B"])
print np.repeat(x, [2, 3], axis=0)

['A' 'A' 'B' 'B' 'B']