Problem two
to write a function named collatz (), which has a parameter named number. If the argument is an even number, then Collatz () to print out the number // 2, and returns the value. If the number is odd, collatz () to print and return 3 * number + 1. Then write a program that allows the user to enter an integer, and continue to call this number collatz (), until the function returns a value of 1 (Surprisingly, this sequence is valid for any integer, use this sequence, you will sooner or later get 1 ! even mathematicians can not determine why. your program in the study of so-called "Collatz sequence," it is sometimes called the "most simple, impossible math problem").
def collatz(number):#定义函数
try:
new_num=int(number)#判断num是否为正整数
except:
print('请输入正整数')#显示出错原因
else:
new_num=new_num%2#偶数余数为0，其他为奇数
if not new_num: #偶数
number=int(number)//2
else:#奇数
number=int(number)*3+1
print(number)
return number
# number=input('输入整数')
# nex=collatz(number)#初始赋值
#判断nex是否为整数并且不等于0
# if isinstance(nex,int)and int(number) != 0:
# while nex !=1:
# nex=collatz(nex)#循环赋值
