Python 3.x 带循环和决策树的小解算器程序，为什么不工作？

如果您能帮助我解决此代码中的错误，我将非常感激

while循环不起作用

当程序要求计算时，它停止

总体思路是让这个小程序在计算过程中帮助我，如果可能的话，还可以添加一个可视化界面

def cycle():
while True:
    newcalc = input('Do you want to make a new calculation? \n \t (Y/N)')
    if newcalc.lower() in ["no","n"]:
        newcalc = "no"
        break
    if newcalc.lower() in ["yes","y"]:
        newcalc = "yes"
    else:
        print('This is not the right answer')

def counting_M():
  while True:
    concersion_1 = input('Do you want to convert from M to uM? (Y/N)')
    if concersion_1.lower() in ["y", "yes"]:
       print('This is the result of the conversion {} uM',   str(data/1000)).format(data)
    mw = input('What is the Molecular Weight of your compound, please in g/M?')
    print('Your coumpound weights ug/ml', str((data) / (mw / 1000))).format(data)
    if mw in float:
        print('The data you have entered is not numeric')
        break
data = input('Please, provide the absolute amount of compound you have, without units \n \t')
units = input('Please, indicate the measure unit you have \n  A)M, B)mM, C)uM '
          '\n 1A)g/liter, 2A)mg/ml, 3A)ug/ml \n \t')
if units.lower() == "a" :
 print('Ok so you have M')
 counting_M()
 cycle()   

---

谢谢你

你做错了几件事：

• def cycle（）

  不返回

  newcalc

  ，呈现其赋值 无用，因为它在函数之外的任何地方都不可见

  循环

• 似乎您正在分配

  数据

  两次，同时 未从

  字符串

  转换为

  浮点

  ，这会使

  打印崩溃

  命令，无论何时返回算术运算（即。，

  str（（数据）/（mw/1000））

  ）
• 如果浮动中的mw不存在，则行

  
  检查
  mw
  是否为
  float
  。使用
  try/except

例如：

try:
    float('0.001')
except ValueError:  # occurs when the string cannot be converted to a  valid float)
    print('Not a valid float string!')

虽然我不清楚您到底想要实现什么，但这段代码应该完成您在示例中尝试的所有事情

def cycle():
    choice = None
    while not choice:
        newcalc = input('Do you want to make a new calculation? \n \t (Y/N)')
        if newcalc.lower() in ["no", "n"]:
            choice = "no"

        if newcalc.lower() in ["yes", "y"]:
            choice = "yes"
        else:
            print('This is not the right answer')
            continue
    return choice

def counting_M(data):
    while True:
        concersion_1 = input('Do you want to convert from M to uM? (Y/N)')
        if concersion_1.lower() in ["y", "yes"]:
            print('This is the result of the conversion {} uM'.format(str(data/1000)))
        else:
            print('Not converting')
        while True:
            mw = input('What is the Molecular Weight of your compound, please in g/M?')
            try:
                mw = float(mw)
                break
            except ValueError:
                print("Not a valid float!")

        print('Your coumpound weights ug/ml', str((data) / (mw / 1000)))

if __name__ =='__main__':
    while True:
        data = input('Please, provide the absolute amount of compound you have, without units \n \t')
        try:
            data = float(data)
            break
        except ValueError:
            print("Not a valid float value!")

    counting_M(data)
    choice = cycle()
    print(choice)

---

什么是

单位

？什么是

mw\u计算
？请把缩进的部分修好。这至少在两个方面是错误的，目的是在我必须测试化合物时，为我做一些非常方便的计算。非常感谢你。你们的代码很清楚，我不熟悉，除了继续一个。