Python进阶之路（目前小白白i=3,...）

2023年3月2日 260次阅读来源: 梅子酒好喝嘛

进阶第一步：Python编程从入门到实践

你知道，就算大雨让这座城市颠倒，我也会……

接上次的第六章开始啦！

6.3 遍历字典

如果需要遍历字典中的所有键值对，可以使用方法items（），它返回一个键值对列表。

>>> use_0={
	'username':'efermi',
	'first':'enrico',
	'last':'fermi',
	}
>>> for key ,value in use_0.items():
	print('\nKey: '+key)
	print('Value: '+value)


Key: username
Value: efermi

Key: first
Value: enrico

Key: last
Value: fermi
>>> #再次印证了Python中的字典不关心键值对的存储顺序，而只追踪键和对之间的关联关系。

如果只需要遍历字典中的键，则可以使用方法keys（）；如果只要遍历字典中的值，则可以使用方法values（）。

>>> friends=['phil','sarch']
>>> favourite_languages={
	'jen':'python',
	'sarah':'c',
	'edward':'ruby',
	'phil':'python',
	}
>>> for name in favourite_languages.keys():
	print(name.title())
	if name in friends:
		print('Hi '+name.title()+
		      ',I see your favourite language is '+
		      favourite_languages[name].title()+'!')

Jen
Sarah
Edward
Phil
Hi Phil,I see your favourite language is Python!

>>> for name in sorted(favourite_languages.keys()):
	print(name.title()+',thanks you for taking the poll.')

Edward,thanks you for taking the poll.
Jen,thanks you for taking the poll.
Phil,thanks you for taking the poll.
Sarah,thanks you for taking the poll.

>>> for value in favourite_languages.values():
	print(value.title())

Python
C
Ruby
Python
>>> for value in set(favourite_languages.values()):
	print(value.title())

C
Python
Ruby
>>> #set 可以让Python过滤掉重复的值，找出列表中独一无二的元素，并使用这些元素创建一个集合。
>>>

所谓嵌套，可以是一系列的字典存储到列表中，也可以是列表存储到字典中，还可以是字典存储到字典中。

学习到现在了，最痛苦的是什么呢？就是想了许多好玩的，看了许多好玩的，可是自己不会用啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊！！！

今天没时间看第七章的了，就这样吧！

If you are still looking for that one person who will change your life, take a look in the mirror!

先到这了，纯小白下次再来！

喜欢梅子酒，喜欢进步的你！

附：输错的代码，提醒自己！

Python 3.6.1 (v3.6.1:69c0db5, Mar 21 2017, 17:54:52) [MSC v.1900 32 bit (Intel)] on win32
Type "copyright", "credits" or "license()" for more information.
>>> use_0={
	'username':'efermi',
	'first':'enrico',
	'last':'fermi',
	}
>>> for key ,value in use_0.items():
	print('\nKey: '+key)
	print('Value: '+value)


Key: username
Value: efermi

Key: first
Value: enrico

Key: last
Value: fermi
>>> 
>>> favourite_languages={
	'jen':'python',
	'sarah':'c',
	'edward':'ruby',
	'phil':'python',
	}
>>> friends=['phil','sarch']
>>> for name in favourite_languages.key():
	print(name.tilte())
	if name in friends:
		print('Hi '+name.title()+
		      ',I see your favourite language is '+
		      favourite_languages[name].title()+'!')

Traceback (most recent call last):
  File "<pyshell#23>", line 1, in <module>
    for name in favourite_languages.key():
AttributeError: 'dict' object has no attribute 'key'
>>> friends=['phil','sarch']
>>> for name in favourite_languages.keys():
	print(name.tilte())
	if name in friends:
		print('Hi '+name.title()+
		      ',I see your favourite language is '+
		      favourite_languages[name].title()+'!')
		
SyntaxError: multiple statements found while compiling a single statement
>>> favourite_languages={
	'jen':'python',
	'sarah':'c',
	'edward':'ruby',
	'phil':'python',
	}
>>> friends=['phil','sarch']
>>> for name in favourite_languages.keys():
	print(name.tilte())
	if name in friends:
		print('Hi '+name.title()+
		      ',I see your favourite language is '+
		      favourite_languages[name].title()+'!')
		
SyntaxError: multiple statements found while compiling a single statement
>>> 
>>> friends=['phil','sarch']
>>> favourite_languages={
	'jen':'python',
	'sarah':'c',
	'edward':'ruby',
	'phil':'python',
	}
>>> for name in favourite_languages.keys():
	print(name.tilte())
	if name in friends:
		print('Hi '+name.title()+
		      ',I see your favourite language is '+
		      favourite_languages[name].title()+'!')

		
Traceback (most recent call last):
  File "<pyshell#32>", line 2, in <module>
    print(name.tilte())
AttributeError: 'str' object has no attribute 'tilte'
>>> friends=['phil','sarch']
>>> favourite_languages={
	'jen':'python',
	'sarah':'c',
	'edward':'ruby',
	'phil':'python',
	}
SyntaxError: multiple statements found while compiling a single statement
>>>  friends=['phil','sarch']
 
SyntaxError: unexpected indent
>>> friends=['phil','sarch']
>>> favourite_languages={
	'jen':'python',
	'sarah':'c',
	'edward':'ruby',
	'phil':'python',
	}
>>> for name in favourite_languages.keys():
	print(name.title())
	if name in friends:
		print('Hi '+name.title()+
		      ',I see your favourite language is '+
		      favourite_languages[name].title()+'!')

Jen
Sarah
Edward
Phil
Hi Phil,I see your favourite language is Python!
>>> friends=['phil','sarch']
>>> favourite_languages={
	'jen':'python',
	'sarah':'c',
	'edward':'ruby',
	'phil':'python',
	}
SyntaxError: multiple statements found while compiling a single statement
>>> friends=['phil','sarch']
>>>  favourite_languages={
	'jen':'python',
	'sarah':'c',
	'edward':'ruby',
	'phil':'python',
	}
 
SyntaxError: unexpected indent
>>> favourite_languages={
	'jen':'python',
	'sarah':'c',
	'edward':'ruby',
	'phil':'python',
	}
>>> for name in favourite_languages.keys():
	print(name.title())

Jen
Sarah
Edward
Phil
>>> for name in favourite_languages.keys():
	print(name.title())
if name in friends:
		print('Hi '+name.title()+
		      ',I see your favourite language is '+
		      favourite_languages[name].title()+'!')
		
SyntaxError: invalid syntax
>>> for name in favourite_languages.keys():
	print(name.title())

	
Jen
Sarah
Edward
Phil
>>> favourite_languages
{'jen': 'python', 'sarah': 'c', 'edward': 'ruby', 'phil': 'python'}
>>> for name in sorted(language_language.keys()):
	print(name.title()+',thanks you for taking the poll.')

Traceback (most recent call last):
  File "<pyshell#54>", line 1, in <module>
    for name in sorted(language_language.keys()):
NameError: name 'language_language' is not defined
>>> for name in sorted(favourite_language.keys()):
	print(name.title()+',thanks you for taking the poll.')

Traceback (most recent call last):
  File "<pyshell#56>", line 1, in <module>
    for name in sorted(favourite_language.keys()):
NameError: name 'favourite_language' is not defined
>>> for name in sorted(favourite_languages.keys()):
	print(name.title()+',thanks you for taking the poll.')

Edward,thanks you for taking the poll.
Jen,thanks you for taking the poll.
Phil,thanks you for taking the poll.
Sarah,thanks you for taking the poll.
>>> for value in favourite_languages.values():
	print(value.title())

Python
C
Ruby
Python
>>> for value in set(favourite_languages.values()):
	print(value.title())

C
Python
Ruby
>>> #set 可以让Python过滤掉重复的值，找出列表中独一无二的元素，并使用这些元素创建一个集合。
>>> 
 RESTART: C:/Users/Administrator/AppData/Local/Programs/Python/Python36-32/天气.py 
Traceback (most recent call last):
  File "C:/Users/Administrator/AppData/Local/Programs/Python/Python36-32/天气.py", line 2, in <module>
    import winshell
ModuleNotFoundError: No module named 'winshell'
>>>

    原文作者：梅子酒好喝嘛
    原文地址: https://zhuanlan.zhihu.com/p/29521131
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进阶第一步：Python编程 从入门到实践

6.3 遍历字典

进阶第一步：Python编程从入门到实践