1. Define a generator function

Generate 1-10
Use next(generator) Method to get 1-10
Use for Cycle to get

def generator():
    for i in range(1, 11):
        yield i


gen = generator()
print(next(gen))
print(next(gen))
print(next(gen))
print(next(gen))
print(next(gen))
print(next(gen))
print(next(gen))
print(next(gen))
print(next(gen))
print(next(gen))

2. simulation range The function of , Build a range:MyRange

range(10)
range(1, 10)
range(1, 10, 1) =>
start, stop, step
range(10, 1, -1)
range(10, -1, -1)
range(-10, -1, 1)
range(-1, -10, -1)

class MyRange:
    def __init__(self, start, stop, step=0):
        self.start = start
        self.stop = stop
        self.step = step

    def __iter__(self):
        return self

    def __next__(self):
        if self.step == 0:
            self.step = 1
        if self.step > 0:
            if self.start < self.stop:
                se = self.start
                self.start += self.step
                return se
            else:
                raise StopIteration
        else:
            if self.start > self.stop:
                se = self.start
                self.start += self.step
                return se
            else:
                raise StopIteration


print(list(MyRange(10, 1, -1)))
print(list(MyRange(10, -1, -1)))
print(list(MyRange(-10, -1, 1)))
print(list(MyRange(-1, -10, -1)))

3. re The use of functions in ( Write your own use cases to use )：

""" match fullmatch search findall finditer split sub subn complie """
print(re.match('pattern', 'pattern asdf'))
print(re.match('pattern', 'paasdern asdf'))
print(re.fullmatch("pattern", 'pattern'))
print(re.fullmatch("pattern", 'pattern asdf'))
print(re.search("pattern", "asdpatternads"))
print(re.search("pattern", "asdpaternads"))
print(re.findall('pattern', "pattern pattern asdpattern"))
iter_or = re.finditer("pattern", "pattern pattern asdpattern")
for i in iter_or:
    print(i)
print(re.split(r'\.', 'asd.txt'))
print(re.sub('pattern', '.', "pattern pattern asdpattern"))
print(re.subn('pattern', '.', "pattern pattern asdpattern"))
print(re.compile('asd'))