python列表部分源码分析

1 def append(self, p_object): # real signature unknown; restored from __doc__
2         """ L.append(object) -- append object to end """
3         pass

#1、练习（添加元素）：
li = [11,22,33,"aabc","cddg",234,"alex",]
print(li)
aa = li.append(78)    #在列表后添加列表元素，注意一次只能添加一个元素，否则报错
print(li)
#执行结果如下：
[11,22,33,"aabc","cddg",234,"alex",]
[11, 22, 33, ‘aabc‘, ‘cddg‘, 234, ‘alex‘, 78]

1 def count(self, value): # real signature unknown; restored from __doc__
2         """ L.count(value) -> integer -- return number of occurrences of value """
3         return 0

1 #2、练习（计算列表元素出现个数）
2 li = [11,22,33,"aabc","cddg",33,"alex",]
3 aa = li.count(33)    #计算列表中指定元素出现的个数,一次只能计算一个元素
4 print(aa)
5 #执行结果如下：
6 2

1 def extend(self, iterable): # real signature unknown; restored from __doc__
2         """ L.extend(iterable) -- extend list by appending elements from the iterable """
3         pass

1 #3、练习（列表扩展（向后））
2 li = [11,22,33,"aabc","cddg",33,"alex",]
3 li.extend("kkk")    #在列表后扩展,一次只能计算一个元素，字符串会拆分一个个显示
4 print(li)
5 li.extend(1234)     #如果扩展整型数字会报错，数字不可拆分
6 print(li)
7 #执行结果：
8 [11, 22, 33, ‘aabc‘, ‘cddg‘, 33, ‘alex‘, ‘k‘, ‘k‘, ‘k‘]
9 报错：TypeError: ‘int‘ object is not iterable

1 def index(self, value, start=None, stop=None): # real signature unknown; restored from __doc__
2         """
3         L.index(value, [start, [stop]]) -> integer -- return first index of value.
4         Raises ValueError if the value is not present.
5         """
6         return 0

1 #4、练习（找出列表元素索引位置）
2 li = [11,22,33,"aabc","cddg",33,"alex",]
3 aa = li.index(22)
4 print(aa)
5 bb = li.index(33)
6 print(bb)     #查找列表中元素的索引，重复存在则输出靠前的索引位置
7 #执行结果：
8 1
9 2

1 def insert(self, index, p_object): # real signature unknown; restored from __doc__
2         """ L.insert(index, object) -- insert object before index """
3         pass

1 #5、练习（插入元素）
2 li = [11,22,33,"aabc","cddg",33,"alex",]
3 li.insert(1,"kkk")       #根据列表下标位置，直接插入
4 print(li)
5 #执行结果：
6 [11, ‘kkk‘, 22, 33, ‘aabc‘, ‘cddg‘, 33, ‘alex‘]

1 def pop(self, index=None): # real signature unknown; restored from __doc__
2         """
3         L.pop([index]) -> item -- remove and return item at index (default last).
4         Raises IndexError if list is empty or index is out of range.
5         """
6         pass

1 #6、练习（取出元素）
2 li = [11,22,33,"aabc","cddg",33,"alex",]
3 li.pop(3)      #取出（删除）指定下标的元素
4 print(li)
5 li.pop()       #如果不输入下标，则默认取出最后一个元素，注意：超出下标范围会报错
6 print(li)
7 #执行结果：
8 [11, 22, 33, ‘cddg‘, 33, ‘alex‘]
9 [11, 22, 33, ‘cddg‘, 33]

1 def remove(self, value): # real signature unknown; restored from __doc__
2         """
3         L.remove(value) -- remove first occurrence of value.
4         Raises ValueError if the value is not present.
5         """
6         pass

1 #练习7、（移除元素）
2 li = [11,22,33,"aabc","cddg",33,"alex",]
3 li.remove(33)      #移除元素，如果有重复的，则移除靠前的那个
4 print(li)
5 #执行结果：
6 [11, 22, ‘aabc‘, ‘cddg‘, 33, ‘alex‘]

1 def reverse(self): # real signature unknown; restored from __doc__
2         """ L.reverse() -- reverse *IN PLACE* """
3         pass

1 练习8、（翻转列表）
2 li = [11,22,33,"aabc","cddg",33,"alex",]
3 li.reverse()    #翻转列表元素顺序
4 print(li)
5 #执行结果：
6 [‘alex‘, 33, ‘cddg‘, ‘aabc‘, 33, 22, 11]

1 def sort(self, cmp=None, key=None, reverse=False): # real signature unknown; restored from __doc__
2         """
3         L.sort(cmp=None, key=None, reverse=False) -- stable sort *IN PLACE*;
4         cmp(x, y) -> -1, 0, 1
5         """
6         pass

#练习9、（列表重新排序）
#li = [11,22,33,"aabc","cddg",33,"alex",]   报错
# li.sort()
# print(li)
aa = ["kkk","bbb","jjj","www"]     #列表按照ASCII码，重新排序，注意：列表里的元素只能全是字符串，或者全是数字，否则会报错
aa.sort()
print(aa)
#执行结果：
[‘bbb‘, ‘jjj‘, ‘kkk‘, ‘www‘]