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今回はパイソンの数値計算のプログラムのサンプルコードを試してみたいと思います。

#!/usr/local/python

print('2+1 =', 2+1)
print('10-3 =', 10-3)
print('7*4 =', 7*4)
print('5/2 =', 5/2)
print('5//2 =', 5//2)
print('10%3 =', 10%3)
print('2**10 =', 2**10)
[user@localhost basic]$ python ensan.py
2+1 = 3
10-3 = 7
7*4 = 28
5/2 = 2.5
5//2 = 2
10%3 = 1
2**10 = 1024


九九計算

#!/usr/local/bin/python

for x in range(0,9):
    for y in range(0,9):
            print('{0}'.format('%2d ' % ((x+1) * (y+1))), end="")
    print('')

[user@localhost basic]$ python 99.py
 1 2 3 4 5 6 7 8 9
 2 4 6 8 10 12 14 16 18
 3 6 9 12 15 18 21 24 27
 4 8 12 16 20 24 28 32 36
 5 10 15 20 25 30 35 40 45
 6 12 18 24 30 36 42 48 54
 7 14 21 28 35 42 49 56 63
 8 16 24 32 40 48 56 64 72
 9 18 27 36 45 54 63 72 81

円周率

#!/usr/local/bin/python

import sys
import math

#
# Machin's formula
# π/4 = 4 * Arctan(1/5) - Arrctan(1/239)
#

def arctan(x, k):
    arctanx = 0
    for n in range(0, k):
        arctanx += pow(-1, n) * (1/(2 * (n+1) - 1)) * pow(x, (2*(n+1) - 1))
    return arctanx

if __name__ == '__main__':
    argv = sys.argv

    if len(argv) != 2:
        print('usage : {0} <n>'.format(argv[0]))
        quit()

    for k in range(1, int(argv[1])):
        pi = 4 * (4 * arctan(1/5, k) - arctan(1/239, k))

    print(pi)
[user@localhost basic]$ python pi.py 10
3.141592653589836