举栗如下：

names = ["hbb",'tian','bao','cheng']                      # define of list  符号为 [] not () or {}

# find one element

print(names [0])       # hbb   以零作为开始；对照位置查找元素；

# print(names[ ])            # 'list' object is not callable  直接括号无效

# print(names( ))            # 'list' object is not callable  不是（）

# print(names(-1))           # 'list' object is not callable  不是（）

print(names[-1])       # cheng                                是[]

#切片，取多个元素

print(names[1:3])      # ['tian', 'bao']                    including 1,but not including 3      顾头不顾尾

print(names[1:-1])     # ['tian', 'bao']                    including 1,but not inckding -1      顾头不顾尾

print(names[1:])       # ['tian', 'bao', 'cheng']           -1 can be bypass, but including -1   不写-1可以去到尾（这样写可以取到最后一个）

print(names[0:3])      # ['hbb', 'tian', 'bao']

print(names [:3])      # ['hbb', 'tian', 'bao']              0  can 省略   不写0 和 不写-1的情况不同：写不写0，都能取0;但是写不写-1却很不同。

print(names[:])        # ['hbb', 'tian', 'bao', 'cheng']     0 and -1 all could bypass

#print(names[ ])             # 'list' object is not callable  [] 里面有点才好使

print(names[0:3:2])    # ['hbb', 'bao']                      步长取样

print(names[::2])      # ['hbb', 'bao']                      0 and -1 all could bypass

print(names)