iPython 在打印斐波那契数列时崩溃

Question

While attempting to print a fibonacci series using tuples, iPython tends to crash.

Here is the code I am trying to execute.

n = raw_input("Please enter a number: ")

a = 0
b = 1
while b < n:
    (b,a) = (a,b+a)
    print b

However, if I replace n with a number (eg. 20, 100, 1000), it runs smoothly. I also tried to run this code in Pycharm, with similar results. Pycharm ran the code, with a huge stream on numbers being generated, and a warning which read:

Too much output to process

What causes this crash?

Answer 1

You forgot to turn the string n you get from raw_input into an integer.

Since the comparison is done by type name in this case b < n will always be True .

Use n = int(raw_input("Please enter a number: "))

Answer 2

因为raw_input的返回值是str，你应该试试n = int(raw_input("Please enter a number: ")) 。