Efficient method to calculate the rank vector of a list in Python

Question

I\'m looking for an efficient way to calculate the rank vector of a list in Python, similar to R\'s rank function. In a simple list with no ties between the ele

Answer 1

This is one of the functions that I wrote to calculate rank.

def calculate_rank(vector):
  a={}
  rank=1
  for num in sorted(vector):
    if num not in a:
      a[num]=rank
      rank=rank+1
  return[a[i] for i in vector]

input:

calculate_rank([1,3,4,8,7,5,4,6])

output:

[1, 2, 3, 7, 6, 4, 3, 5]