Python full stack path-list (Day 04)

1. Two methods of listing 1. Built-in methods for lists

2. Add to List

   格式：x.__add__(y)等同于x+y例如：list1 = [1,2,3]     print(list1.__add__([4,5,6])) >>> [1,2,3,4,5,6]返回值：list

   Note: The preceding y can be list/tuple/str/dict/set and so on, but it cannot be int.

4. Whether it is an inclusive relationship

   格式：x.__contains__(y)等同于y in x例如：list1 = [1,2,3]     print(list1.__contains__([2,3])) >>> True返回值：bool

   Note: The preceding y can be list/tuple/str/dict/set and so on, but it cannot be int.

6. Specify list index deletions (modify original list)

   格式：x.__delitem__(index)等同于delete x[index]例如：list1 = [1,2,3]     list1.__delitem__(2)     print(list1) >>> [1,2]返回值：None

8. Determine if two lists are equal

   格式：x.__eq__(y)等同于x==y例如：list1 = [1,2,3]     print(list1.__eq__([2,3])) >>> False返回值：bool

10. Determine if list 1 is greater than or equal to List 2

    格式：x.__ge__(y)等同于x>=y例如：list1 = [1,2,3]     print(list1.__ge__([1,2])) >>> True返回值：bool

    Note: This method is primarily judged by the first element of the list

12. Methods for accessing properties

    格式：x.__getitem__(index)等同于x[index]例如：list1 = [1,2,3]     print(list1.__getitem(2)) >>> 3返回值：object

14. Determine if list 1 is greater than List 2

    格式：x.__gt__(y)等同于x>y例如：list1 = [1,2,3]     print(list1.__gt__([2])) >>> False返回值：bool

    Note: This method is primarily judged by the first element of the list

16. Add Value of Assignment

    格式：x.__iadd__(y)等同于x += y例如：list1 = [1,2,3]     print(list1__iadd__(‘3‘)) >>> [1, 2, 3, ‘3‘]返回值：list

    Note: The preceding y can be list/tuple/str/dict/set, but not int, and the original list will change.

18. Multiply the assignment value

    格式：x.__imul__(num)等同于x *= num例如：list1 = [1,2,3]     print(list1.__imul__(2)) >>> [1,2,3,1,2,3]返回值：list

    Note:num can only be of type int, and the original list will change.

20. Constructor method (Modify the original list)

    格式：x.__init__(y)例如：list1 = [1,2,3]     list1.__init__([4,5])     print(list1) >>> [4,5]返回值：list

    Note:y does not specify to construct an empty list

22. Iterators

    格式：x.__iter__()等同于iter(x)例如：list1 = [1,2,3]     die = list1.__iter__()     print(die.__next__()) >>> 1返回值：迭代器

24. Determine if list 1 is less than or equal to List 2

    格式：x.__le__(y)等同于x<=y例如：list1 = [1,2,3]     print(list1.__le__([2])) >>> True返回值：bool

    Note: This method is primarily judged by the first element of the list

26. List length

    格式：x.__len__()等同于len(x)例如：list1 = [1,2,3]     print(list1.__len__()) >>> 3返回值：int

28. Determine if list 1 is less than List 2

    格式：x.__lt__(y)等同于x<y例如：list1 = [1,2,3]     print(list1.__lt__([2])) >>> True返回值：bool

    Note: This method is primarily judged by the first element of the list

30. Multiplication of lists

    格式：x.__mul__(num)等同于x*y例如：list1 = [1,2,3]     print(list.__mul__(2)) >>> [1,2,3,1,2,3]返回值：list

32. Determine if two lists are not equal

    格式：x.__ne__(y)等同于x!=y例如：list1 = [1,2,3]     print(list1.__ne__([4,5])) >>> True返回值：bool

34. Redefining a list

    格式：x.__new__(list)例如：list1 = [1,2,3]     print(list1.__new__(list)) >>> []返回值：list

36. Built-in transformations

    格式：x.__reversed__()等同于reversed(x)例如：list1 = [1,‘2‘,3,‘d‘,‘$‘]     die = list1.__reversed__()     print(die.__next__()) >>> ‘$‘返回值：迭代器

38. Right → Multiply left list

    格式：x.__rmul__(num)等同于num*x例如：list1 = [1,2,3]     print(list1.__rmul__(2)) >>> [1,2,3,1,2,3]返回值：list

40. Modify the elements of the specified index (modify the original list)

    格式：x.__getitem__(index,value)等同于x[index]=value例如：list1 = [1,2,3]     list1.__getitem__(1,5)     print(list1) >>> [1,5,3]返回值：None

42. List in memory size, converted to bytes for calculation

    格式：x.__sizeof__()例如：list1 = [1,2,3]     list2 = [2,3]     print(list1.__sizeof__()) >>> 64     print(list2.__sizeof__()) >>> 56       返回值：int#列表长度的不同，导致类别在内存中的大小也不一样。

2. Common methods

2. Add an element to the original list

   格式：x.append(y)    #直接修改原列表，添加的元素可以任意对象，每次只能添加一个元素例如：list1 = [1,2,3,4]     list1.append([1,2,3])     print(list1) >>> [1,2,3,4,[1,2,3]]返回值：None

4. Clear the original list

   格式：x.clear()    #删除列表中所有元素，列表本身不删除例如：list1 = [1,2,3,4]     list1.clear()     print(list1) >>> []返回值：None

6. Copy List

   格式：x.copy()    #复制原列表，生成一个新列表例如：list1 = [1,2,3,4]     print(list1.copy()) >>> [1,2,3,4]返回值：list

8. Count

   格式：x.count(value)    #统计列表中指定元素的个数例如：list1 = [1,2,2,3,4,2,3]     print(list1.count(2)) >>> 3返回值：int

10. Expand list

    格式：x.extend()    #在原列表中扩充列表(修改原列表)，两个列表合并为一个列表例如：list1 = [1,2,3,4]     list1.extend([‘1‘,‘2‘])     print(list1) >>> [1, 2, 3, 4, ‘1‘, ‘2‘]返回值：None

12. Removes the index of the specified element value

    格式：x.index(value,strat,end)     #在指定的索引范围内，查找元素的索引，默认全列表查找例如：list1 = [1, 2, 3, 4, ‘1‘, ‘2‘]     print(list1.index(‘1‘,2,5)) >>> 4返回值：int

14. inserting elements

    格式：x.insert(index,object)    #在原列表中，指定索引位置处添加一个元素，元素可以是任意对象例如：list1 = [1, 2, 3, 4, ‘1‘, ‘2‘]     list1.insert(3,‘four‘)     print(list1) >>> [1, 2, 3, ‘four‘, 4, ‘1‘, ‘2‘] 返回值：None

16. Remove the value of the specified index

    格式：x.pop(index)    #删除指定索引的值，默认从列表的最后面开始删除例如：list1 = [1, 2, 3, ‘four‘, 4, ‘1‘, ‘2‘]     print(list1.pop()) >>> ‘2‘     print(list1.pop(2)) >>> 3     print(list1) >>> [1, 2, ‘four‘, 4, ‘1‘]返回值：object

18. To remove the specified element

    格式：x.remove(value)    #删除指定元素，直接修改原列表例如：list1 = [1, 2, 3, ‘four‘, 4, ‘1‘, ‘2‘]     list1.remove(3)     print(list1) >>> [1, 2, ‘four‘, 4, ‘1‘, ‘2‘]返回值：None

20. Reverse

    格式：x.reverse()    #对列表进行升序排序后再进行颠倒例如：list1 = [1, 2, 3, ‘four‘, 4, ‘1‘, ‘2‘]     list1.reverse()     print(list1) >>> [‘2‘, ‘1‘, 4, ‘four‘, 3, 2, 1]返回值：None

22. Sort Ascending

    格式：x.sort()    #对列表进行升序排序，一般int和str类型不能同时存在例如：list1 = [6,2,3,4]     list1.sort()     print(list1) >>> [2,3,4,6]返回值：None

2. Operation of the list 1. The underlying operation of the list

2. Add to List

   Index operations

   Member detection

   Maximum Value

   注：该函数只能用于纯数字的列表。

4. 转换为列表

   格式：for variable in list: 使用variable 例如：list1 = [1,2,3] for i in list1: print(i) >>> 1 >>> 2 >>> 3

6. while looping through

         Format: variable = 0 while variable < len (list): Use elements in List (list[variable]) variable + = 1 For example: List1 = [+/-] i = 0 while I < Len (list1): print (List1[i]) i + = 1 >>> 1 >>> 2 >>> ; 3      

8. 二级列表的遍历

   1. 格式：for variable1 in list: for variable2 in variable1: 使用variable 例如：list1 = [[‘a‘,‘b‘,‘c‘],[‘d‘,‘e‘,‘f‘],[‘g‘,‘h‘,‘i‘]] for i in list1: for j in i: print(j) #输出的j就是大列表中列表的元素2. 格式：for variable1,variable2,... in list: 直接使用variable1,variable2,... 例如：list1 = [[‘a‘,‘b‘,‘c‘],[‘d‘,‘e‘,‘f‘],[‘g‘,‘h‘,‘i‘]] for n1,n2,n3 in list1: print(n1) >>> ‘a‘ >>> ‘d‘ >>> ‘g‘

   注：方法2只能遍历同等长度的二级列表。

9. 列表推导式

   2. 简单的列表推导式

      格式：[variable for variable in list]例如：list1 = [1,3,4,5] print([i for i in list1]) >>> [1,3,4,5]返回值：list#只是把原来的列表遍历了一遍，生成了和原列表一样的列表

   4. 稍作修改的列表推导式

      格式：[‘*‘+variable+‘*‘ for variable in list]例如：list1 = [‘a‘,‘b‘,‘c‘] print([‘*‘+i+‘*‘ for i in list1]) >>> [‘*a*‘, ‘*b*‘, ‘*c*‘]返回值：list#对variable进行修改，可以是int的操作，也可以是str的操作，具体需根据列表元素来执行

   6. 带有判断条件的列表推导式

      格式：[variable for variable in list if 条件表达式]例如：list1 = [2,3,4,2,1,2,23,54,21,33] print([i for i in list1 if i>20]) >>> [23, 54, 21, 33]返回值：list

   8. 多个列表推导式

      格式：[variable1+variable2 for variable1 in list1 for variable2 in list2]例如：list1 = [‘a‘,‘b‘,‘c‘] list2 = [‘I‘,‘love‘,‘you‘,‘!‘] print([x+y for x in list1 for y in list2]) >>> [‘aI‘, ‘alove‘, ‘ayou‘, ‘a!‘, ‘bI‘, ‘blove‘, ‘byou‘, ‘b!‘, ‘cI‘, ‘clove‘, ‘cyou‘, ‘c!‘]返回值：list

   10. 带有判断条件的多个列表推导式

       格式：[variable1+variable2 for variable1 in list1 for variable2 in list2 if 条件表达式]例如：list1 = [‘a‘,‘b‘,‘c‘] list2 = [‘I‘,‘love‘,‘you‘,‘!‘] print([x+y for x in list1 for y in list2 if list1.index(x)==list2.index(y)]) >>> [‘aI‘, ‘blove‘, ‘cyou‘]返回值：list

Turn from: Python Changes the life--Introduction to the list in Python

Python full stack path-list (Day 04)