def reverse( x):
"""
:type x: int
:rtype: int
"""
num = 0
if x == 0:
return 0
if x < 0:
x = -x
while x != 0:
num = num*10 + x%10
x = x//10
num = -num
else:
while x != 0:
num = num*10 + x%10
x = x//10
if num>pow(2,31)-1 or num < pow(-2,31):
return 0
return num
# print(reverse(-261))
def fib(n):
if n == 0:
return False
if not isinstance(n, int) or (abs(n) != n):
return False
if n <= 1:
return n
return fib(n-1)+ fib(n-2)
# print([fib(i) for i in range(1, 11)])
33、正則切分字符串
import re
str1 = 'li‵‵‵uleqian songjianguo: qinyeyang'
result = re.split(r":| ", str1)
# print(result)
34、yield
# yield 是用來生成迭代器的語法,在函數中,如果包含了 yield,那麼這個函數就是一個迭代器。
# 當代碼執行至 yield 時,就會中斷代碼執行,直到程序調用 next() 函數時,纔會在上次 yield 的地方繼續執行
def foryield():
print("start test yield")
while True:
result = yield 5
print("result:", result)
g = foryield()
# print(next(g))
# print("*"*20)
# print(next(g))