为什么008和009 Python Python的无效键？ [英] Why are 008 and 009 invalid keys for Python dicts?

问题描述

为什么我不能将008或009作为Python dict的键，但001-007是否正常？
示例：

  some_dict = {
 001：spam，
 002：鸡蛋，
 003：foo，
 004：bar，
 008：anything，＃抛出一个SyntaxError 
 009：nothing＃抛出一个SyntaxError 
} 
  

更新：问题解决。我没有意识到开始一个零的字面值使它八进制。这似乎很奇怪为什么零？

解决方案

在python和其他一些语言中，如果您使用0启动一个数字，则该数字被解释为八进制基数8），其中只有0-7是有效数字。您必须将代码更改为：

  some_dict = {
 1：spam，
 2：egg，
 3：foo，
 4：bar，
 8：anything，
 9：nothing} 
  

或者如果前导零是非常重要的，请使用字符串进行密钥。

Why is it that I can't have 008 or 009 be keys for a Python dict, but 001-007 are fine? Example:

some_dict = {
    001: "spam",
    002: "eggs",
    003: "foo",
    004: "bar",
    008: "anything", # Throws a SyntaxError
    009: "nothing"   # Throws a SyntaxError
    }

Update: Problem solved. I wasn't aware that starting a literal with a zero made it octal. That seems really odd. Why zero?

解决方案

In python and some other languages, if you start a number with a 0, the number is interpreted as being in octal (base 8), where only 0-7 are valid digits. You'll have to change your code to this:

some_dict = { 
    1: "spam",
    2: "eggs",
    3: "foo",
    4: "bar",
    8: "anything",
    9: "nothing" }

Or if the leading zeros are really important, use strings for the keys.

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