Page 267 - Computer Science Class 11 Without Functions
P. 267

I am Good,    Sir,
                 How are you
            To remove the whitespace only from the beginning or end of the string, we use the Python string methods lstrip()
            and rstrip(), as illustrated below:

             >>> '       Hello How are you!      '.lstrip()
                 'Hello How are you!      '
             >>> '       Hello How are you!      '.rstrip()
                 '       Hello How are you!'

                  s.isupper(): Tests whether the string comprises only uppercase characters.
                  s.islower(): Tests whether the string comprises only lowercase characters.
                  s.isalpha(): Tests whether a string comprises only alphabets.
                  s.isdigit(): Tests whether a string comprises only digits.
                  s.isalnum(): Tests whether a string contains only alphabets and digits.
                  s.isspace(): Tests whether a string comprises only whitespace characters.
                  s.startswith(subStr): Tests whether the string s starts with the string subStr, passed as a parameter.
                  s.endswith(subStr): Tests whether the string s ends with the suffix subStr, passed as a parameter.

            ●  s.isupper():  The  method  isupper()  tests  whether  the  string  comprises  only  uppercase  characters.  For
              example,

             >>> msg1 = 'SURAIYAJABIN'
             >>> msg1.isupper()
                 True
             >>> msg2 = 'SuraiyaJabin'
             >>> msg2.isupper()
                 False
            As  the  string  msg1  comprises  all  uppercase  letters,  when  the  method  isupper()  is  applied  to  it,  the  method
            returns True. However, as string msg2 comprises a mix of uppercase and lowercase characters, when the method

            isupper() is applied to it, the method returns False.
            ●  s.islower()The method islower() tests whether the string comprises only lowercase characters, For example,
             >>> msg1 = 'suraiyajabin'
             >>> msg1.islower()
                 True
             >>> msg2 = 'SuraiyaJabin'
             >>> msg2.islower()
                 False
            As the string msg1 comprises all lowercase letters, when the method islower()  is applied to it, the method
            returns True. However, since the string msg2 comprises a mix of uppercase and lowercase characters, when the

            method islower() is applied to it, the method returns False.
            ●  s.isalpha(): The method isalpha() checks whether a string comprises only alphabets, for example,
             >>> 'SuraiyaJabin'.isalpha()
                 True
             >>> 'Suraiya Jabin'.isalpha()
                 False
            In the first function call, the method isalpha() returned True as the string comprises only the alphabets of the
            English language. However, the second function call returned False because the string included a space.
            ●  s.isdigit(): The method isdigit() checks whether a string comprises only digits. For example,
             >>> '9898989898'.isdigit()
                 True
            The above function call returns True  since the string '9898989898' is composed of digits only. However, the
            following function call returns False as the string includes the symbols + and -, apart from the digits.



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