我决定将一个计算器作为一个项目。 实现基本的加，减，除和乘法非常容易。
我想添加更多功能，所以我决定在用户视图中实现结果列表。但是，我很难用数字方式跟踪结果。我写了一个迷宫的if语句，这些语句可以起作用，但是似乎已被代码过度使用。我相信有更好的方法来解决这个问题。
有什么建议吗？
def add(x, y):
return x + y
def sub(x, y):
return x - y
def mul(x, y):
return x * y
def div(x, y):
value = None
while True:
try:
value = x / y
break
except ZeroDivisionError:
print('Value is not dividable by 0, try again')
break
return value
def num_input(prompt='Enter a number: '):
while True:
try:
print(prompt, end='')
x = int(input())
break
except ValueError:
print('You must input a number. Try again.')
return x
def get_two_val():
x, y = num_input(), num_input()
return x, y
print("Welcome to Simple Calc")
# declaration of variables
num_of_calc_counter = 0
index_of_calc = 1
calculations = []
while True:
print("Choose from the following options:")
print(" 1. Add")
print(" 2. Subtract")
print(" 3. Multiply")
print(" 4. Divide")
print(" 5. Sales Tax Calculator")
print(" 6. Recent Calculations")
print(" 0. Quit")
usrChoice = num_input('Enter your choice: ')
'''
Menu workflow
options 1-4 take in two numbers and perform the specified calculation and
then add the result to a master list that the user can reference later.
lastly, the workflow increments the num_of_calc variable by 1 for recent
calc logic
option 5 is a simple tax calculator that needs work or option to enter
or find tax rate
option 6 returns a list of all the calculations perform by the user
'''
if usrChoice is 1:
numbers = get_two_val()
result = add(*numbers)
print(numbers[0], "plus", numbers[1], "equals", result)
calculations.extend([result])
num_of_calc_counter += 1
elif usrChoice is 2:
numbers = get_two_val()
result = sub(*numbers)
print(numbers[0], "minus", numbers[1], "equals", result)
calculations.extend([result])
num_of_calc_counter += 1
elif usrChoice is 3:
numbers = get_two_val()
result = mul(*numbers)
print(numbers[0], "times", numbers[1], "equals", result)
calculations.extend([result])
num_of_calc_counter += 1
elif usrChoice is 4:
numbers = get_two_val()
result = div(*numbers)
print(numbers[0], "divided by", numbers[1], "equals", result)
calculations.extend([result])
num_of_calc_counter += 1
elif usrChoice is 5:
tax_rate = .0875
price = float(input("What is the price?: "))
total_tax = tax_rate * price
final_amount = total_tax + price
print('Tax rate: ', tax_rate, '%')
print('Sales tax: $', total_tax)
print('_____________________________')
print('Final amount: $', final_amount)
#
elif usrChoice is 6:
if len(calculations) is 0:
print('There are no calculations')
elif num_of_calc_counter == 0:
index_of_calc = 1
for i in calculations:
print(index_of_calc, i)
index_of_calc += 1
num_of_calc_counter += 1
elif index_of_calc == num_of_calc_counter:
index_of_calc = 1
for i in calculations:
print(index_of_calc, i)
index_of_calc += 1
num_of_calc_counter += 1
elif num_of_calc_counter > index_of_calc:
index_of_calc = 1
for i in calculations:
print(index_of_calc, i)
index_of_calc += 1
num_of_calc_counter -= 1
elif num_of_calc_counter < index_of_calc:
index_of_calc = 1
for i in calculations:
print(index_of_calc, i)
index_of_calc += 1
num_of_calc_counter += 1
elif usrChoice is 0:
break
答案 0 :(得分：0)
我不知道您是否能找到更简单的方法：
def num_input(prompt='Enter a number: '):
finished = False
while not finished:
string_input = input(prompt)
try:
input_translated = int(string_input)
except ValueError:
print('You must input a number. Try again.')
else:
finished = True
return input_translated
def division_operation(x, y):
if y == 0:
print('Value is not dividable by 0, try again')
return None
else:
return x / y
math_operations_values = [
(lambda x, y: x + y, 'plus'),
(lambda x, y: x - y, 'minus'),
(lambda x, y: x * y, 'times'),
(division_operation, 'divided by')
]
def get_two_val():
return (num_input(), num_input())
def operate_on_numbers(operation_index):
def operate():
numbers = get_two_val()
operator, operation_string = math_operations_values[operation_index]
result = operator(*numbers)
if result is not None:
print(numbers[0], operation_string, numbers[1], "equals", result)
calculations.append(result)
return operate
def tax_computation():
tax_rate = .0875
price = float(input("What is the price?: "))
total_tax = tax_rate * price
final_amount = total_tax + price
print('Tax rate: ', tax_rate * 100, '%')
print('Sales tax: $', total_tax)
print('_____________________________')
print('Final amount: $', final_amount)
def show_computations():
if calculations:
for (index, values) in enumerate(calculations, start=1):
print(f'{index}: {values}')
else:
print('There are no calculations')
calculations = []
finished = False
choices_actions = [
operate_on_numbers(0),
operate_on_numbers(1),
operate_on_numbers(2),
operate_on_numbers(3),
tax_computation,
show_computations
]
while not finished:
print("""
Choose from the following options:
1. Add
2. Subtract
3. Multiply
4. Divide
5. Sales Tax Calculator
6. Recent Calculations
0. Quit""")
user_choice = num_input('Enter your choice: ')
'''
Menu workflow
options 1-4 take in two numbers and perform the specified calculation and
then add the result to a master list that the user can reference later.
lastly, the workflow increments the num_of_calc variable by 1 for recent
calc logic
option 5 is a simple tax calculator that needs work or option to enter
or find tax rate
option 6 returns a list of all the calculations perform by the user
'''
if user_choice == 0:
finished = True
else:
try:
operation_to_do = choices_actions[user_choice - 1]
except IndexError:
print('Please enter one of choice shown.')
else:
operation_to_do()