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

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

The Python "AttributeError: 'str' object has no attribute 'uppercase'" occurs when we try to call the uppercase() method on a string. To solve the error, use the upper() method to uppercase a string, e.g. 'abc'.upper().

Here is an example of how the error occurs.

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my_str = 'hello world'

# ⛔️ AttributeError: 'str' object has no attribute 'uppercase'
result = my_str.uppercase()

Strings don't have an uppercase() method in Python, however you can use the upper() method to uppercase a string.

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my_str = 'hello world'

result = my_str.upper()

print(result)  # 👉️ "HELLO WORLD"

The str.upper method returns a copy of the string with all the cased characters converted to uppercase.

Make sure to store the result in a variable as the original string remains unchanged.

Conversely, you can use the lower() method to convert a string to lowercase.

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my_str = 'HELLO WORLD'

result = my_str.lower()

print(result)  # 👉️ "hello world"

The str.lower method returns a copy of the string with all the cased characters converted to lowercase.

You can use the str.title() method to get the titlecased version of a string.

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my_str = 'james doe'

result = my_str.title()

print(result)  # 👉️ "James Doe"

The str.title method returns a titlecased version of the string where words start with an uppercase character and the remaining characters are lowercase.

Note that the algorithm also converts characters after apostrophes to uppercase.

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my_str = "it's him"

result = my_str.title()

print(result)  # 👉️ "It'S Him"

The string.capwords method doesn't have this problem, as it only splits words on spaces.

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from string import capwords

my_str = "it's him"

result = capwords(my_str)

print(result)  # 👉️ "It's Him"

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 uppercase() method, the error is caused.