python提示 write() argument must be str, not method
时间: 2023-06-13 16:03:15 浏览: 56
这个错误提示意味着你在尝试将一个方法作为参数传递给 `write()` 函数,但是 `write()` 函数需要的是一个字符串参数。要解决这个问题,你需要确保将方法调用的结果转换为字符串,然后将字符串传递给 `write()` 函数。
例如,如果你正在尝试将一个对象的方法作为参数传递给 `write()` 函数,你可以这样做:
```python
myfile.write(str(myobject.mymethod()))
```
这里,`myobject.mymethod()` 返回一个方法,但是 `str()` 函数将其转换为字符串,然后将字符串传递给 `write()` 函数。这样就可以避免 `write() argument must be str, not method` 的错误提示了。
相关问题
write() argument must be str, not generator
This error occurs when you try to pass a generator object as an argument to the built-in `write()` function in Python. The `write()` function is used to write data to a file object or a stream, and it expects a string as its argument.
Here's an example of how this error can occur:
```
# Example 1: Passing a generator to write()
def my_generator():
yield 'Hello'
yield 'world'
with open('output.txt', 'w') as f:
f.write(my_generator()) # ERROR: write() argument must be str, not generator
```
In this example, we define a generator function `my_generator()` that yields two strings: "Hello" and "world". We then try to write the output of this generator to a file using the `write()` function, which results in the error message "write() argument must be str, not generator".
To fix this error, we need to convert the generator output to a string before passing it to `write()`. One way to do this is to use the `join()` method of the string object to concatenate the generator output into a single string:
```
# Example 2: Converting generator output to string before passing to write()
def my_generator():
yield 'Hello'
yield 'world'
with open('output.txt', 'w') as f:
f.write(''.join(my_generator())) # OK: generator output is concatenated into a single string
```
In this example, we use the `join()` method to concatenate the output of the `my_generator()` function into a single string, which we then pass to the `write()` function. This should write the string "Helloworld" to the file "output.txt".
write() argument must be str, not None
This error occurs when you try to pass a None value as an argument to the write() method, which expects a string as input.
To fix this error, make sure that the argument you're passing to the write() method is not None. You can do this by checking the value of the variable or expression you're passing as an argument.
For example:
```
my_string = None
if my_string is not None:
file.write(my_string)
```
In this example, we check if the value of my_string is not None before passing it to the write() method.
Alternatively, you can set a default value for the argument to avoid passing None:
```
def my_function(my_string=None):
if my_string is not None:
file.write(my_string)
```
In this example, we set the default value of my_string to None, but check if it's not None before passing it to the write() method.