Python连续语法错误？

Question

我一直在尝试用Python在我的Raspberry Pi上做一个转换程序。出于某种原因，每当我尝试运行代码时，它都会在前6行没有错误的情况下运行，然后在之后的每一行都会出错。我正在使用python3，我看不出它为什么要这样做。你知道吗

#Defining Conversion Function
def convert():
    #Millimeter Conversions
    #It gets through this line of code here
    unit = input('Please enter your unit conversion in the form unit1:unit2 (ex. cm:in)'.lower()
#Then errors out here
    number = input('Please enter your first number')

    if unit == 'mm:cm':
        newnumber = float(number) / 10
        print (newnumber)
    elif unit == 'mm:dm':
        newnumber = float(number) / 100
        print (newnumber)
    elif unit == 'mm:m':
        newnumber = float(number) / 1000
        print (newnumber)
    elif unit == 'mm:dkm':
        newnumber = float(number) / 10000
        print (newnumber)
    elif unit == 'mm:hm':
        newnumber = float(number) / 100000
        print (newnumber)
    elif unit == 'mm:km':
            newnumber = float(number) / 1000000
            print (newnumber)

    #Centimeter Conversions    
    if unit == 'cm:mm':
        newnumber = float(number) * 10
        print(newnumber)
    elif unit == 'cm:dm':
        newnumber = float(number) / 10
        print (newnumber)
    elif unit == 'cm:m':
        newnumber = float(number) / 100
        print (newnumber)
    elif unit == 'cm:dkm':
        newnumber = float(number) / 1000
        print (newnumber)
    elif unit == 'cm:hm':
        newnumber = float(number) / 10000
        print (newnumber)
    elif unit == 'cm:km':
        newnumber = float(number) / 100000
        print (newnumber)

#Defining the Scientific Notation Function
def sn():
    sn = input ('Pease enter you Scientific Notation string')
    print ('%0.10f' % x)

Answer 1

在lower()之前的单元初始化中缺少)。应该是这样的：

unit = input('Please enter your unit conversion in the form unit1:unit2 (ex. cm:in)').lower()