AttributeError: ‘str’ 对象没有属性 ‘write’

AttributeError: ‘str’ object has no attribute ‘write’

Python“AttributeError: ‘str’ object has no attribute ‘write’” 发生在我们write()对字符串（例如文件名）而不是文件对象调用方法时。要解决该错误，请write()在打开文件后调用文件对象上的方法。

attributeerror str 对象没有属性写入

下面是错误如何发生的示例。

主程序


file_name = 'example.txt'

with open(file_name, 'w', encoding='utf-8') as my_file:
    # ⛔️ AttributeError: 'str' object has no attribute 'write'
    file_name.write('first line' + '\n')
    file_name.write('second line' + '\n')
    file_name.write('third line' + '\n')

问题是我们write()在文件名上调用了方法，它是一个字符串。

相反，write()在打开文件对象后调用该方法。

主程序


file_name = 'example.txt'

with open(file_name, 'w', encoding='utf-8') as my_file:
    # ✅ calling write() on file object
    my_file.write('first line' + '\n')
    my_file.write('second line' + '\n')
    my_file.write('third line' + '\n')

with open()即使抛出异常，语法也会自动关闭文件。

或者，您可以将文件对象存储到变量中并手动关闭它。

主程序


file_name = 'example.txt'

my_file = open(file_name, 'w', encoding='utf-8')

my_file.write('first line' + '\n')
my_file.write('second line' + '\n')
my_file.write('third line' + '\n')

my_file.close()

请注意，最好使用with open()语法，因为它会在我们完成后自动关闭文件。

如果需要将数据附加到文件，请使用a标志而不是w.

主程序


file_name = 'example.txt'

with open(file_name, 'a', encoding='utf-8') as my_file:
    my_file.write('first line' + '\n')
    my_file.write('second line' + '\n')
    my_file.write('third line' + '\n')

如果您需要从文件读取和写入文件，请使用该r+标志。

主程序


file_name = 'example.txt'

with open(file_name, 'r+', encoding='utf-8') as my_file:
    read_data = my_file.read()
    print(read_data)

    my_file.write('first line' + '\n')
    my_file.write('second line' + '\n')
    my_file.write('third line' + '\n')

开始调试的一个好方法是print(dir(your_object))查看字符串具有哪些属性。

这是打印 a 的属性的示例string。

主程序


my_string = 'hello world'

# [ 'capitalize', 'casefold', 'center', 'count', 'encode', 'endswith', 'expandtabs', 'find', 'format',
#  'format_map', 'index', 'isalnum', 'isalpha', 'isascii', 'isdecimal', 'isdigit', 'isidentifier',
#  'islower', 'isnumeric', 'isprintable', 'isspace', 'istitle', 'isupper', 'join', 'ljust', 'lower',
#  'lstrip', 'maketrans', 'partition', 'removeprefix', 'removesuffix', 'replace', 'rfind', 'rindex',
#  'rjust', 'rpartition', 'rsplit', 'rstrip', 'split', 'splitlines', 'startswith', 'strip', 'swapcase',
#  'title', 'translate', 'upper', 'zfill']
print(dir(my_string))

If you pass a class to the
dir() function, it
returns a list of names of the class’s attributes, and recursively of the
attributes of its bases.

If you try to access any attribute that is not in this list, you would get the “AttributeError: str object has no attribute error”.

Since the str object doesn’t implement a write() method, the error is
caused.

Conclusion #

The Python “AttributeError: ‘str’ object has no attribute ‘write'” occurs when
we call the write() method on a string (e.g. the filename) instead of a file
object. To solve the error, call the write() method on the file object after
opening the file.

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