CODEWITHSUNDEEP
pythonstringpython-3.x
mc-lunar
mc-lunar

Reputation: 293

Why am I getting "isupper is not defined" error?

learning python and working with some basic string methods.

I have this program which finds the index of the first lowercase char in a string:

def find_lower(word):
i = 0
while not isupper(word[i]):
    i = i+1
return i

however, when I run this code, I get the error 

builtins.NameError: name 'isupper' is not defined

Do I need to import a module or something for isupper() to work?

Upvotes: 1

Views: 4880

Answers (4)

Paul Rooney
Paul Rooney

Reputation: 21609

You are using isupper incorrectly. It is not a built in standalone function. It is a method of str. The documentation is here.

For any function that you are unsure of you can consult the python documentation. It is well indexed by google so a google search is a good place to begin when you want to understand how to use a function.

Once that is out of the way, your find_lower has a few more issues. It actually finds the index of the first upper case letter due to a logic error.

while not word[i].isupper():

Continues to loop if the character is not upper case and stops if it is. So you need to remove the not.

def find_lower(word):
    i = 0
    while word[i].isupper():
        i = i+1
    return i

print(find_lower('ABcDE')) # prints 2

The next error is that if there are no lowercase characters it walks off the end of the string and throws an exception 

>print(find_lower('ABCDE'))
Traceback (most recent call last):
  File "./myisupper.py", line 11, in <module>
    print(find_lower('ABCDE'))
  File "./myisupper.py", line 5, in find_lower
    while word[i].isupper():
IndexError: string index out of range

To fix this you need to limit the number of iterations to the length of the string, this is left as an exercise to fix.

Upvotes: 4

rawwar
rawwar

Reputation: 4992

isupper is a method of string. so, you should use it on a string

For example,

a = "Hello"

#You can check upper on this as follows
print(a.isupper())

In your case, change the following 

while not isupper(word[i]):

to 

while not word[i].isupper():
    print("Your x here")

Upvotes: 3

Mureinik
Mureinik

Reputation: 311508

isupper is a method of string, and should be called by that object: word[i].isupper().

Upvotes: 2

Nihal
Nihal

Reputation: 5334

it should be like

def find_lower(word):
  i = 0
  while not word[i].isupper():
      i = i+1
  return i

Upvotes: 1

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