PythonStudy——列表的常用操作 List of common operations

# 1.索引取值: 列表名[index]

s1 = [1, 3, 2]
print(s1[0])
print(s1[-1])

# 2.列表运算: 得到的是新list

s2 = [1, 2, 3]
print(s2 + s2)
print(s2 * 2)
print(s2)

# 3.list的长度

s3 = [3, 4, 1, 2, 5]
print(len(s3))

# 4.切片：[start_index:end_index:step]

s4 = [3, 4, 1, 2, 5]
new_s4 = s4[::-1]
print(new_s4)
new_s4 = s4[1:4:]
print(new_s4)
new_s4 = s4[-2:-5:-1]
print(new_s4)

# 5.成员运算：in

s5 = [3, 4, '', 2, 5]
print('' in s5)
print(1 in s5)
print(5 not in s5)

# 6.循环

for v in s5:
    print(v, type(v))

# 只打印数字类型的数据

for v in s5:
    if isinstance(v, int):
        print(v, end=' ')