Page 313 - Computer Science Class 11 With Functions
P. 313
>>> 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.
>>> '+91-9898989898'.isdigit()
False
● s.isalnum(): A valid user name may be allowed to contain only alphabets and digits. The method isalnum()
enables us to check whether the username entered by a user comprises only alphabets and digits. For example,
>>> userId = 'Prodyot123'
>>> userId.isalnum()
True
>>> password = 'secret@123'
>>> password.isalnum()
False
Note that the first function call userId.isalnum() returns True as the string userId comprises only
alphabets and digits. However, password.isalnum() yields False as the string password includes a special
character @.
● s.isspace(): The method isspace() returns True if the string comprises only whitespace characters and
False otherwise. For example,
>>> ' '.isspace()
True
>>> ' '.isspace()
True
>>> ' \t\n'.isspace()
True
>>> ' hello '.isspace()
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