莫烦 Python 基础 其他语句

我的视频学习笔记
continue

while True:
    b = input('type something: ')
    if b == '1':
        continue  # 直接跳过后面的while语句 重新开始while循环
    else:
        pass
    print('still in while')
print('finish run')

输出：

type something: 2
still in while
type something: 1
type something: 

break

while True:
    b = input('type something: ')
    if b == '1':
        break  # 直接跳出while循环
    else:
        pass
    print('still in while')
print('finish run')

输出：

type something: 2
still in while
type something: 1
finish run

错误处理 Try except else搭配用法

# file = open('eeee', 'r')  # FileNotFoundError: [Errno 2] No such file or directory: 'eeee'
try:
    file = open('eeee', 'r+')  # 读＋写的方法打开eeee这个名字的文件
except Exception as e:  # 如果没有这个这个文件进入异常处理
    print(e)
    print('there is no file named as eeee')
    response = input('do you want to create a new file ? y/n：')  # 是否要新建一个名字为eeee的文件
    if response == 'y':
        file = open('eeee', 'w')
        file.close()
    else:
        pass
else:
    file.write('ssss')  # 如果有这个文件 就往里面写入ssss
file.close()

浅复制与深复制 copy

# copy
import copy
a = [1, 2, 3]
b = a  # 将两个索引绑在一起 完全copy 同一个存储空间
print(id(a))
print(id(b))
b[0] = 11
print(a)
a[1] = 22
print(b)
print(id(a) == id(b))
c = copy.copy(a)  # 浅复制 
print(id(a) == id(c))
c[1] = 2222
print(a)
print(c)

a = [1, 2, [3, 4]]
d = copy.copy(a)
print(id(a) == id(d))
print(id(a[2]) == id(d[2]))
a[0] = 111
print(a)
print(d)
a[2][0] = 333
print(a)
print(d)
e = copy.deepcopy(a)  # 深复制 地址完全不重复 任何东西都不会存到同一个内存空间
print(id(a[2]) == id(e[2]))

输出：

2555426810440
2555426810440
[11, 2, 3]
[11, 22, 3]
True
False
[11, 22, 3]
[11, 2222, 3]
False
True
[111, 2, [3, 4]]
[1, 2, [3, 4]]
[111, 2, [333, 4]]
[1, 2, [333, 4]]
False