python 'str' object has no attribute 'withdraw'

在Python中，`str` 对象是一个字符串类型的数据结构，它不具备像 `withdraw` 这样的属性或方法。当你尝试在一个字符串上执行如 `withdraw` 这样的操作时，会抛出 "AttributeError"，因为字符串没有这样的功能。例如，如果 `withdraw` 是某个类（比如银行账户类）的方法，你应该先确保你在对一个实例对象而不是字符串上调用。

相关问题

python为什么报错str object has no attribute readlines

这个错误是因为 `readlines` 是 `file` 对象的方法，而 `str` 对象没有 `readlines` 方法。因此，当你尝试在 `str` 对象上调用 `readlines` 方法时，Python 就会报告这个错误。

如果你想从一个字符串中读取多行文本，可以使用 `splitlines` 方法。例如，你可以使用以下代码来读取一个字符串中的多行文本：

text = "This is line 1.\nThis is line 2.\nThis is line 3."
lines = text.splitlines()

这将把 `text` 字符串中的每一行文本分割成一个列表 `lines` 中的单独字符串元素。

str object has no attribute setex

The error message "str object has no attribute setex" means that you're trying to call the setex method on a string object, but this method is not defined for strings.

The setex method is a Redis command that sets a value in a Redis database with an expiration time. To use this method in Python, you need to first connect to a Redis server using a Redis client library such as redis-py, and then call the setex method on the Redis client object.

Here's an example of how to use the setex method with redis-py:

import redis

r = redis.Redis(host='localhost', port=6379, db=0)
r.setex('mykey', 60, 'myvalue')

This code connects to a Redis server running on localhost:6379, selects database 0, and then sets the key 'mykey' with the value 'myvalue' and an expiration time of 60 seconds.

Make sure you have installed redis-py library before running this code.