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我正在尝试编写一个将十六进制转换为十进制的函数。我有两个问题。我无法用数字替换所有字母。它替换了一个字母，然后停止。其次，我如何得到它以便它连续添加每个整数？

 def toDecimal(hexidecimal):
    decimal=[hexidecimal[i:i+1] for i in range(0,len(hexidecimal), 1)]
    for i in range(0,len(decimal)):
            if 'a' in decimal:
                decimal[i]='10'
            if 'b' in decimal:
                decimal[i]='11'
            if 'c' in decimal:
                decimal[i]='12'
            if 'd' in decimal:
                decimal[i]='13'
            if 'e' in decimal:
                decimal[i]='14'
            if 'f' in decimal:
                decimal[i]='15'
            return decimal
      #Above I try to convert any letters into a number value 
    for i in range(0,len(decimal)):
        converted_decimal=decimal[i]*(16**i)
        total_decimal=converted_decimal+converted_decimal
    return total_decimal
     #Here I'm trying to add each converted decimal
4

4 回答 4

2

我认为阅读这个惯用的 Python 教程会对您有所帮助：http: //python.net/~goodger/projects/pycon/2007/idiomatic/handout.html

def hex2dec(hexadecimal):
    conversion_table = {'A': 10, 'B': 11, 'C': 12, 'D': 13, 'E': 14, 'F': 15}

    hex_list = list(hexadecimal)

    for index, number in enumerate(hex_list):
        number = number.upper()   

        if number in conversion_table:
            hex_list[index] = conversion_table[number]

    int_list = [int(number) for number in hex_list]

    return reduce(lambda x, y: x*16+y, int_list)


print hex2dec('7Ac8965f')    # 2059966047
于 2013-10-15T09:20:39.147 回答
2

你的代码有很多问题。让我们来看看：

hexidecimal= "7ac8965f" #hexadecimal value

decimal=[hexidecimal[i:i+1] for i in range(0,len(hexidecimal), 1)]
# >> decimal : ["7","a","c","8","9","6","5","f"]

for i in range(0,len(decimal)):
# first path : i = 0

        # First Error : 'in' is a array-wide search.
        # you want to use :'if decimal[i] == 'a' '
        if 'a' in decimal: # a is in decimal (second pos) so decimal[0] is modified !
            decimal[i]='10'
            # >> decimal : ["10","a","c","8","9","6","5","f"]

        if 'b' in decimal:
            decimal[i]='11'
        if 'c' in decimal:
            decimal[i]='12'
        if 'd' in decimal:
            decimal[i]='13'
        if 'e' in decimal:
            decimal[i]='14'
        if 'f' in decimal: # f is in decimal (last pos) so decimal[0] is modified !
            decimal[i]='15'
            # >> decimal : ["15","a","c","8","9","6","5","f"]

        #Second Error : anticipated return
        #Assuming the indentation is correct, the function exit here, on the 
        #first run of the function
        return decimal

现在一个解决方案：

#dict for conversion (there are more elegant ways to do it, 
#                                                        but this is good enough)
conversion_table = { '0' : 0 ,
                     '1' : 1 ,
                     '2' : 2 ,
                     '3' : 3 ,
                      .......
                     'a' : 10 ,
                     'b' : 11 ,
                     ......
                     'f' : 15
                    }

hexidecimal= "7ac8965f" #hexadecimal value

hexa_list=[ digit for digit in hexidecimal]
# same thing as before, just more "elegant"

decimal = [ conversion_table[hex_digit] for hex_digit in hexa_list]
# convert everything in base10

# reduce the list
return reduce( lambda x,y : x*16 + y, decimal )
于 2013-10-15T08:22:23.710 回答
1

我只是在这里玩得开心，但是要重写您的功能...

def toDecimal(hexadecimal):
    decimal = int(hexadecimal, 16)
    return decimal

toDecimal('0xdeadbeef')

我假设您正在重新发明轮子只是为了看看它是如何完成的？:)

于 2013-10-15T08:20:53.120 回答
0

有一种更简单的方法可以做到这一点：

大的东西：

>>> s = "6f48f8248e828ce82f82"
>>> int(s, 16)
525528725744949635067778L

更小的东西：

>>> int('BF', 16)
191

在数字前添加 a0x不会改变最终结果。

作为一个函数：

def hex2dec(s):
    """return the integer value of a hexadecimal string s"""
    return int(s, 16)
于 2013-10-15T08:14:52.167 回答