Write a Python function to check a sequence of numbers is an arithmetic progression or not.

Solution

def is_arithmetic(l):
    delta = l[1] - l[0]
    for index in range(len(l) - 1):
        if not (l[index + 1] - l[index] == delta):
             return False
    return True
def is_geometric(li):
    if len(li) <= 1:
        return True
    # Calculate ratio
    ratio = li[1]/float(li[0])
    # Check the ratio of the remaining
    for i in range(1, len(li)):
        if li[i]/float(li[i-1]) != ratio: 
            return False
    return True