Python - Math - Working with Numbers(Give Exit Power to the User)

Doing Math with Python
(No Starch Press)
Amit Saha (著)

開発環境

• OS X El Capitan - Apple (OS)
• Emacs (Text Editor)
• Python 3.5 (プログラミング言語)

Doing Math with Python: Use Programming to Explore Algebra, Statistics, Calculus, and More! (Amit Saha (著)、No Starch Press)のChapter 1.(Working with Numbers)、Programming Challenges #4: Give Exit Power to the User(No. 793)を解いてみる。

#4: Give Exit Power to the User(No. 813)

コード(Emacs)

#!/usr/bin/env python3
#-*- coding: utf-8 -*-

def roots(a, b, c):
    D = (b ** 2 - 4 * a * c) ** 1.5
    x_1 = (- b + D) / (2 * a)
    x_2 = (- b - D) / (2 * a)

    print('x1: {0}'.format(x_1))
    print('x2: {0}'.format(x_2))

if __name__ == '__main__':
    while True:
        print('ax^2 + bx + c = 0')
        a = input('Enter a: ')
        b = input('Enter b: ')
        c = input('Enter c: ')
        roots(float(a), float(b), float(c))
        answer = input('Do you want to exit? (y) for yes: ')
        if answer == 'y':
            break

入出力結果(Terminal, IPython)

$ ./sample5.py
ax^2 + bx + c = 0
Enter a: 1
Enter b: 2
Enter c: 3
x1: (-1.000000000000002-11.313708498984761j)
x2: (-0.9999999999999979+11.313708498984761j)
Do you want to exit? (y) for yes: n
ax^2 + bx + c = 0
Enter a: 1
Enter b: 2
Enter c: 1
x1: -1.0
x2: -1.0
Do you want to exit? (y) for yes: y
$