typeerror：不能将序列乘以“int”类型的非int

Question

I am brand new to python (and programming in general) and I am following examples from Python Programming: An Introduction to Computer Science John M. Zelle, Ph.D. Version 1.0rc2 Fall 2002 Obviously this is quite a bit out of date and I am using Python 3.3 I am typing in the exercise exactly as the book shows it (adding () around the print statements) but I keep coming up with the error. Here is a copy of what I input and the result when I tried to run the program. What am I doing wrong?

>>> def main():
    print ("This program illustrates a chaotic function.")
    x=input ("Enter a number between 0 and 1:")
    for i in range(10):
        x= 3.9*x*(1-x)
        print (x)


>>> main()
This program illustrates a chaotic function.
Enter a number between 0 and 1:1
Traceback (most recent call last):
  File "<pyshell#12>", line 1, in <module>
    main()
  File "<pyshell#11>", line 5, in main
    x= 3.9*x*(1-x)
TypeError: can't multiply sequence by non-int of type 'float'
>>> 

Answer 1

use x=float(input ("Enter a number between 0 and 1:")) as input() returns a string in python 3k not float :

>>> def main():
...     print ("This program illustrates a chaotic function.")
...     x=float(input ("Enter a number between 0 and 1:"))
...     for i in range(10):
...         x= 3.9*x*(1-x)
...         print (x)
... 
>>> main()
This program illustrates a chaotic function.
Enter a number between 0 and 1:.45
0.96525
0.13081550625
0.443440957341
0.962524191305
0.140678352587
0.47146301943
0.971823998886
0.106790244894
0.372005745109
0.911108135788