AttributeError: 'str' object has no attribute 'reverse'

AttributeError: 'str' object has no attribute 'reverse' #

The Python "AttributeError: 'str' object has no attribute 'reverse'" occurs when we call the reverse() method on a string. To solve the error, use string slicing to reverse a string, e.g. 'abc'[::-1].

Here is an example of how the error occurs.

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my_str = 'apple'

# ⛔️ AttributeError: 'str' object has no attribute 'reverse'
print(my_str.reverse())

Strings don't have a reverse() method in Python, however we can use string slicing to reverse a string.

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my_str = 'apple'

reversed_str = my_str[::-1]

print(reversed_str)  # 👉️ "elppa"

The syntax for string slicing is my_str[start:stop:step].

We omitted the indices for start and stop because we want the whole string.

The original string remains unchanged, so make sure to store the reversed string in a variable.

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my_str = 'abc'

reversed_str = my_str[::-1]

print(reversed_str)  # 👉️ "cba"

print(my_str)  # 👉️ "abc"

Note that lists have a reverse() method in Python.

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my_list = ['a', 'b', 'c']

my_list.reverse()

print(my_list)  # 👉️ ['c', 'b', 'a']

The list.reverse() method reverses the elements of the list in place.

The method returns None because it mutates the original list.

A good way to start debugging is to print(dir(your_object)) and see what attributes a string has.

Here is an example of what printing the attributes of a string looks like.

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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 classes' attributes, and recursively of the attributes of its bases.

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