尝试在 python 中输入 object 时出错

Question

我有一个主脚本，它导入了另一个我一直在写的 python 库。该库包含以下命令：

print getattr(__builtins__, "list")

当我从库中调用它时会产生以下错误：

'dict' object has no attribute 'list'

但是，如果我将相同的命令复制并粘贴到主脚本中，它就可以正常工作。知道为什么这不起作用吗？

我的主文件的 header 看起来像这样：

#/usr/bin/env python
from sys import argv
import re, sys, os, argparse
sys.path.extend(map(os.path.abspath, ['C:/Users/xxxx/scripts/modules/']))
import general

我的 "general" 图书馆的 header 是：

#!/usr/bin/env python
from sys import argv
import re, sys, os, argparse

def getBuiltin(name):
    ##Convert a string into an attribute
    try:
        return getattr(__builtins__, name)
    except Exception as e:
        print "Unhandled type in function \"get_builtin\""
        print name
        print e
        exit()

我是这样调用图书馆的：

print general.getBuiltin("list")

其中，"getBuiltin" 是我的函数的名称

Answer 1

你也可以查看这个问题：Python: What's the difference between __builtin__ and __builtins__?

正如您在 akent answer 中看到的，builtins 在主模块和另一个模块中是不同的：

Straight from the python documentation: http://docs.python.org/reference/executionmodel.html

By default, when in the main module, builtins is the built-in module builtin (note: no 's'); when in any other module, builtins is an alias for the dictionary of the builtin module itself.

builtins can be set to a user-created dictionary to create a weak form of restricted execution.

CPython implementation detail: Users should not touch builtins; it is strictly an implementation detail. Users wanting to override values in the builtins namespace should import the builtin (no 's') module and modify its attributes appropriately. The namespace for a module is automatically created the first time a module is imported. Note that in Python3, the module builtin has been renamed to builtins to avoid some of this confusion.

尝试在 python 中输入 object 时出错

Error when trying to get object type in python

python

python-2.7

getattr

built-in