python - 为什么我会收到 TypeError : can't multiply sequence by non-int of type 'float'

Question

我正在尝试执行我在 John Zelle 的 Python 编程:计算机科学导论 中找到的这个示例 Python 脚本:

# File: chaos.py
# A simple program illustrating chatic behavior

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()

...但出于某种原因，我不断收到此错误:

Traceback (most recent call last):
  File "C:\...\chaos.py", line 11, in <module>
    main()
  File "C:\...\chaos.py", line 8, in main
    x = 3.9 * x * (1 - x)
TypeError: can't multiply sequence by non-int of type 'float'

我不知道如何解决这个问题。有什么建议吗？

Answer 1

input() 默认返回一个字符串。在使用它之前，您必须将其转换为 float。

这是 documentation (看起来你正在使用 Python 3.x)

If the prompt argument is present, it is written to standard output without a trailing newline. The function then reads a line from input, converts it to a string (stripping a trailing newline), and returns that. When EOF is read, EOFError is raised.

罪魁祸首是:

x = input("Enter a number between 0 and 1: ")

尝试

x = input("Enter a number between 0 and 1: ")
x = float(x)