arithmetic progression builder (snippet)

Python example 'arithmetic progression builder'

Functions in program:

def arithmetic_p_sequence_builder(a, d, n_last):

arithmetic progression builder

Python beginners example: arithmetic progression builder

#!/usr/bin/python
# -*- coding: utf-8 -*-

# Arithmetic progressions
# are special types of sets(more of a series)
# where the difference between every consecutive
# numbers of series is constant or common
# for more refer: https://en.wikipedia.org/wiki/Arithmetic_progression

# formula for general term of arithmetic prog.
# tn = a + (n - 1) * d
# where, 
#    tn -> is the n(th) term, 
#     a -> if the first term, 
#    d -> is the common difference 

# Third param 'n_last' refers to limit or length or index of last term

def arithmetic_p_sequence_builder(a, d, n_last):

    # To generate an A.P. length should be
    # greater than or equal to 1
    if n_last < 1:
        return -1

    seq = []

    # Every item is obtained by
    # applying the general term formula
    for n in range(1, n_last + 1):
        seq.append(a + (n - 1) * d)

    return seq 

# Test
print("Arithmetic progression: {}".format(arithmetic_p_sequence_builder(int(raw_input("A(a, first term): ")), int(raw_input("D(d, common difference): ")), int(raw_input("N(n, length): ")))))

# Although big line, but works just fine!

Useful links

Learn Python: https://pythonbasics.org
Download Python: https://python.org