# Python 3 Radix Sort Algorithm Script to Sort Number Array in Ascending or Descending Order

## Python 3 Radix Sort Algorithm Script to Sort Number Array in Ascending or Descending Order

``````# Python program for implementation of Radix Sort

# A function to do counting sort of arr[] according to
# the digit represented by exp.
def countingSort(arr, exp1):

n = len(arr)

# The output array elements that will have sorted arr
output = [0] * (n)

# initialize count array as 0
count = [0] * (10)

# Store count of occurrences in count[]
for i in range(0, n):
index = (arr[i]/exp1)
count[int((index)%10)] += 1

# Change count[i] so that count[i] now contains actual
# position of this digit in output array
for i in range(1,10):
count[i] += count[i-1]

# Build the output array
i = n-1
while i>=0:
index = (arr[i]/exp1)
output[ count[ int((index)%10) ] - 1] = arr[i]
count[int((index)%10)] -= 1
i -= 1

# Copying the output array to arr[],
# so that arr now contains sorted numbers
i = 0
for i in range(0,len(arr)):
arr[i] = output[i]

# Method to do Radix Sort

# Find the maximum number to know number of digits
max1 = max(arr)

# Do counting sort for every digit. Note that instead
# of passing digit number, exp is passed. exp is 10^i
# where i is current digit number
exp = 1
while max1/exp > 0:
countingSort(arr,exp)
exp *= 10

# Driver code to test above
arr = [ 170, 45, 75, 90, 802, 24, 2, 66]