Python高级语法与正则表达式(一）

# 1、以写的方式打开文件
with open('1.txt', 'w') as f:
    # 2、读取文件内容
    f.write('hello world')

# 创建生成器
my_generator = (i * 2 for i in range(5))
print(my_generator)
 
# next获取生成器下一个值
# value = next(my_generator)
# print(value)
 
# 遍历生成器
for value in my_generator:
    print(value)

def generator(n):
    for i in range(n):
        print('开始生成...')
        yield i
        print('完成一次...')
        
g = generator(5)
print(next(g))
print(next(g))
print(next(g))
print(next(g))
print(next(g))              ----->    正常
print(next(g))              ----->    报错
Traceback (most recent call last):
  File "/Users/cndws/PycharmProjects/pythonProject/demo.py", line 14, in <module>
    print(next(g))
StopIteration

def generator(n):
    for i in range(n):
        print('开始生成...')
        yield i
        print('完成一次...')
        
g = generator(5)
for i in g:
    print(i)

def example():
    x = 1
    y = 10
    while x < y:
        yield x
        x += 1
 
example = example()
print(example)

def fib(max): 
    n, a, b = 0, 0, 1 
    while n < max: 
        yield b      # 使用 yield
        # print b 
        a, b = b, a + b 
        n = n + 1
 
for n in fib(5): 
    print n