arith_geo.py

#Have the function ArithGeo(arr) take the array of numbers stored in arr and return the string "Arithmetic" 
# if the sequence follows an arithmetic pattern or return "Geometric" if it follows a geometric pattern. 
# If the sequence doesn't follow either pattern return -1. An arithmetic sequence is one where the difference between each of the numbers is consistent, 
# where as in a geometric sequence, each term after the first is multiplied by some constant or common ratio. 
# Arithmetic example: [2, 4, 6, 8] and Geometric example: [2, 6, 18, 54]. Negative numbers may be entered as parameters, 
# 0 will not be entered, and no array will contain all the same elements.
def ArithGeo(arr):
    d = arr[1] - arr[0]
    r = arr[1]/arr[0]
    if all(arr[i+1] - arr[i] == d for i in range(len(arr)-1)):
        return "Arithmetic"
    if all(arr[i+1]/arr[i] == r for i in range(len(arr)-1)):
        return "Geometric"
    
    return '-1'

# keep this function call here 
print(ArithGeo(input()))