Python3---内建函数---dict()
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前言
该文章描述了dict()的使用
2020-01-16
天象独行
0X01;查看函数dict()用法
#!/uer/bin/env python #coding:utf-8 help(dict)
Help on class dict in module builtins: class dict(object) | dict() -> new empty dictionary | dict(mapping) -> new dictionary initialized from a mapping object‘s | (key, value) pairs | dict(iterable) -> new dictionary initialized as if via: | d = {} | for k, v in iterable: | d[k] = v | dict(**kwargs) -> new dictionary initialized with the name=value pairs | in the keyword argument list. For example: dict(one=1, two=2) | | Methods defined here: | | __contains__(self, key, /) | True if the dictionary has the specified key, else False. | | __delitem__(self, key, /) | Delete self[key]. | | __eq__(self, value, /) | Return self==value. | | __ge__(self, value, /) | Return self>=value. | | __getattribute__(self, name, /) | Return getattr(self, name). | | __getitem__(...) | x.__getitem__(y) <==> x[y] | | __gt__(self, value, /) | Return self>value. | | __init__(self, /, *args, **kwargs) | Initialize self. See help(type(self)) for accurate signature. | | __iter__(self, /) | Implement iter(self). | | __le__(self, value, /) | Return self<=value. | | __len__(self, /) | Return len(self). | | __lt__(self, value, /) | Return self<value. | | __ne__(self, value, /) | Return self!=value. | | __repr__(self, /) | Return repr(self). | | __setitem__(self, key, value, /) | Set self[key] to value. | | __sizeof__(...) | D.__sizeof__() -> size of D in memory, in bytes | | clear(...) | D.clear() -> None. Remove all items from D. | | copy(...) | D.copy() -> a shallow copy of D | | get(self, key, default=None, /) | Return the value for key if key is in the dictionary, else default. | | items(...) | D.items() -> a set-like object providing a view on D‘s items | | keys(...) | D.keys() -> a set-like object providing a view on D‘s keys | | pop(...) | D.pop(k[,d]) -> v, remove specified key and return the corresponding value. | If key is not found, d is returned if given, otherwise KeyError is raised | | popitem(...) | D.popitem() -> (k, v), remove and return some (key, value) pair as a | 2-tuple; but raise KeyError if D is empty. | | setdefault(self, key, default=None, /) | Insert key with a value of default if key is not in the dictionary. | | Return the value for key if key is in the dictionary, else default. | | update(...) | D.update([E, ]**F) -> None. Update D from dict/iterable E and F. | If E is present and has a .keys() method, then does: for k in E: D[k] = E[k] | If E is present and lacks a .keys() method, then does: for k, v in E: D[k] = v | In either case, this is followed by: for k in F: D[k] = F[k] | | values(...) | D.values() -> an object providing a view on D‘s values | | ---------------------------------------------------------------------- | Class methods defined here: | | fromkeys(iterable, value=None, /) from builtins.type | Create a new dictionary with keys from iterable and values set to value. | | ---------------------------------------------------------------------- | Static methods defined here: | | __new__(*args, **kwargs) from builtins.type | Create and return a new object. See help(type) for accurate signature. | | ---------------------------------------------------------------------- | Data and other attributes defined here: | | __hash__ = None Process finished with exit code 0
0X02;描述
dict() 函数用于创建一个字典。
0X03;语法
class dict(**kwarg)
class dict(mapping,**kwarg)
class dict(iterable,**kwarg)
参数:
**kwargs -- 关键字
mapping -- 元素的容器。
iterable -- 可迭代对象。
0X04;返回值
返回一个字典
0X05;实例
1;创建空字典
>>> dict()
{}
>>>
2;传入关键字创建字典
>>> dict(a=‘asdf‘,b=‘asdf‘,c=‘werwerf‘) {‘a‘: ‘asdf‘, ‘c‘: ‘werwerf‘, ‘b‘: ‘asdf‘} >>>
3;映射函数方式来构造字典
>>> dict(zip([‘1‘,‘2‘,‘3‘],[‘x‘,‘c‘,‘d‘])) {‘1‘: ‘x‘, ‘3‘: ‘d‘, ‘2‘: ‘c‘} >>>
4;可迭代对象方式来构造字典
>>> dict([(‘a‘,1),(‘b‘,2)]) {‘a‘: 1, ‘b‘: 2} >>>
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