Python 簡易範例學習 命令式計算機

像畫家一樣 臨摹他人程式碼，思考流程

可否反推出流程圖出來呢?

http://pastebin.com/0xMfkrYJ

# Program make a simple calculator
# that can add, subtract, and divide using functions

# define functions


def add(x, y):
    """This function adds two numbers """
    return x + y
# print (add(1,2)) 測試


def subtract(x, y):
    """This function subtracts two numbers"""
    return x - y


def multiply(x, y):
    """ This function multiplies two numbers"""
    return x * y


def divide(x, y):
    """This function divides two numbers"""
    return x * y

# take inpute from the user
print("Select operation.")
print("1.Add")
print("2.Subtract")
print("3.Multiply")
print("4.Divide")

choice = eval(input("Enter choice(1/2/3/4):"))

num1 = int(eval(input("Enter first number: ")))
num2 = int(eval(input("Enter second number: ")))

if choice == 1:
    print(num1, "+", num2, "=", add(num1, num2))
elif choice == 2:
    print((num1, "-", num2, "=", subtract(num1, num2)))
elif choice == '3':
    print((num1, "*", num2, "=", multiply(num1, num2)))
elif choice == '4':
    print((num1, "/", num2, "=", divide(num1, num2)))
else:
    print("Invalid input")


 

    echo "I like PHP";



修正過後的程式

def add(x, y):
    """This function adds two numbers"""
    return x + y

def subtract(x, y):
    """This function subtracts two numbers"""
    return x - y

def multiply(x, y):
    """This function multiplies two numbers"""
    return x * y

def divide(x, y):
    """This function divides two numbers"""
    if y == 0:
        return "Error: Cannot divide by zero!"
    return x / y

# 選擇操作
print("Select operation.")
print("1. Add")
print("2. Subtract")
print("3. Multiply")
print("4. Divide")

choice = input("Enter choice(1/2/3/4):")  # 讀取輸入，字串
num1 = int(input("Enter first number: "))
num2 = int(input("Enter second number: "))

if choice == "1":
    print(num1, "+", num2, "=", add(num1, num2))
elif choice == "2":
    print(num1, "-", num2, "=", subtract(num1, num2))
elif choice == "3":
    print(num1, "*", num2, "=", multiply(num1, num2))
elif choice == "4":
    print(num1, "/", num2, "=", divide(num1, num2))
else:
    print("Invalid input")

print("I like Python")  # 修正 PHP 語法錯誤