1、叠代器

　　（1）可叠代對象

1 s1 = ‘123‘
2 for i in s1:
3     print(i)

　　示例結果：

D:\Python36\python.exe "E:/Python/課堂視頻/day13視頻與課堂筆記/day13課堂筆記/day13/02 叠代器.py"
1
2
3
True
False

Process finished with exit code 0

　　int object is not iterable

1 for i in 123:
2     print(i)

示例結果：

D:\Python36\python.exe "E:/Python/課堂視頻/day13視頻與課堂筆記/day13課堂筆記/day13/02 叠代器.py"
Traceback (most recent call last):
  File "E:/Python/課堂視頻/day13視頻與課堂筆記/day13課堂筆記/day13/02 叠代器.py", line 8, in <module>
    for i in 123:
TypeError: ‘int‘ object is not iterable

Process finished with exit code 
 
1

　　內部含有__iter__方法的就是可叠代對象,遵循可叠代協議。

1 dir
2 print(dir(‘123‘))  # ‘__iter__‘

　　結果：

1 D:\Python36\python.exe "E:/Python/課堂視頻/day13視頻與課堂筆記/day13課堂筆記/day13/02 叠代器.py"
2 [‘__add__‘, ‘__class__‘, ‘__contains__‘, ‘__delattr__‘, ‘__dir__‘, ‘__doc__‘, ‘__eq__‘, ‘__format__
 
‘, ‘__ge__‘, ‘__getattribute__‘, ‘__getitem__‘, ‘__getnewargs__‘, ‘__gt__‘, ‘__hash__‘, ‘__init__‘, ‘__init_subclass__‘, ‘__iter__‘, ‘__le__‘, ‘__len__‘, ‘__lt__‘, ‘__mod__‘, ‘__mul__‘, ‘__ne__‘, ‘__new__‘, ‘__reduce__‘, ‘__reduce_ex__‘, ‘__repr__‘, ‘__rmod__‘, ‘__rmul__‘, ‘__setattr__‘, ‘__sizeof__‘, ‘__str__‘, ‘__subclasshook__‘, ‘capitalize‘, ‘casefold‘, ‘center‘, ‘count‘, ‘encode‘, ‘endswith‘, ‘expandtabs‘, ‘find‘, ‘format‘, ‘format_map‘, ‘index‘, ‘isalnum‘, ‘isalpha‘, ‘isdecimal‘, ‘isdigit‘, ‘isidentifier‘, ‘islower‘, ‘isnumeric‘, ‘isprintable‘, ‘isspace‘, ‘istitle‘, ‘isupper‘, ‘join‘, ‘ljust‘, ‘lower‘, ‘lstrip‘, ‘maketrans‘, ‘partition‘, ‘replace‘, ‘rfind‘, ‘rindex‘, ‘rjust‘, ‘rpartition‘, ‘rsplit‘, ‘rstrip‘, ‘split‘, ‘splitlines‘, ‘startswith‘, ‘strip‘, ‘swapcase‘, ‘title‘, ‘translate‘, ‘upper‘, ‘zfill‘]
3 
4 Process finished with exit code 0

D:\Python36\python.exe "E:/Python/課堂視頻/day13視頻與課堂筆記/day13課堂筆記/day13/02 叠代器.py"
[‘__add__‘, ‘__class__‘, ‘__contains__‘, ‘__delattr__‘, ‘__dir__‘, ‘__doc__‘, ‘__eq__‘, ‘__format__‘, ‘__ge__‘, ‘__getattribute__‘, ‘__getitem__‘, ‘__getnewargs__‘, ‘__gt__‘, ‘__hash__‘, ‘__init__‘, ‘__init_subclass__‘, ‘__iter__‘, ‘__le__‘, ‘__len__‘, ‘__lt__‘, ‘__mod__‘, ‘__mul__‘, ‘__ne__‘, ‘__new__‘, ‘__reduce__‘, ‘__reduce_ex__‘, ‘__repr__‘, ‘__rmod__‘, ‘__rmul__‘, ‘__setattr__‘, ‘__sizeof__‘, ‘__str__‘, ‘__subclasshook__‘, ‘capitalize‘, ‘casefold‘, ‘center‘, ‘count‘, ‘encode‘, ‘endswith‘, ‘expandtabs‘, ‘find‘, ‘format‘, ‘format_map‘, ‘index‘, ‘isalnum‘, ‘isalpha‘, ‘isdecimal‘, ‘isdigit‘, ‘isidentifier‘, ‘islower‘, ‘isnumeric‘, ‘isprintable‘, ‘isspace‘, ‘istitle‘, ‘isupper‘, ‘join‘, ‘ljust‘, ‘lower‘, ‘lstrip‘, ‘maketrans‘, ‘partition‘, ‘replace‘, ‘rfind‘, ‘rindex‘, ‘rjust‘, ‘rpartition‘, ‘rsplit‘, ‘rstrip‘, ‘split‘, ‘splitlines‘, ‘startswith‘, ‘strip‘, ‘swapcase‘, ‘title‘, ‘translate‘, ‘upper‘, ‘zfill‘]

Process finished with exit code 0

2、生成器

3、知識點補充

4、列表推導式，生成器表達式

5、如何系統科學的學習Python

Python全棧__叠代器、生成器、知識點補充、列表推導式，生成器表達式、如何系統科學的學習Python