Page 316 - Computer Science Class 11 With Functions
P. 316
● s.join(list): Joins the strings in the given list (comma-separated sequence of values provided within square
brackets) together using the string s as the delimiter. For example,
>>> '>>'.join(['a', 'b', 'c', 'd'])
'a>>b>>c>>d'
The strings in the list ['a', 'b', 'c', 'd'] are joined together using '>>' as the delimiter.
Next, let us consider an example that uses a space as the delimiter to print the concatenated string that spreads over
multiple lines.
>>> ' '.join(['Hello', '\tHow', 'are', 'you?\n', 'I', 'am', 'fine.\n', 'How', 'are', 'you?'])
'Hello \tHow are you?\n I am fine.\n How are you?'
>>> print(' '.join(['Hello', '\tHow', 'are', 'you?\n', 'I', 'am', 'fine.\n', 'How', 'are',
'you?']))
Hello How are you?
I am fine.
How are you?
Write the names of the functions that will be used to perform the following tasks:
(i) To convert a string to uppercase.
(ii) To find the length of a string.
(iii) To check whether a string consists of digit(s).
(iv) To return a list of words from the string.
(v) To display the index of a character in a string.
(vi) To replace the character in a string with a new character.
(vii) To return a string with the first character of each word capitalized.
(viii) To remove the leading spaces from a string.
12.4 Case Study
In this section, we will develop a module named stringFns.py that enables us to perform the following operations
on strings:
1. Form a string comprising distinct characters in a string, replacing uppercase characters with corresponding
lowercase characters.
2. Compute the number of matching characters in a pair of strings.
3. Find whether a string is a substring of another string.
4. Construct a string by reversing the sequence of the characters in the original string.
12.4.1 Distinct Characters in a String Ignoring the Case
To form a string comprising the distinct characters in a string, let us develop a function distinct() that takes a
string str1 as the input parameter.
● On execution of line 8, a string may comprise a mix of upper and lowercase characters, we first construct a string of
lowercase characters.
● Line 9, we initialize the string of distinct characters (distinctChars) to an empty string.
● On execution of lines 10-12, for every character in the string, if the character is not included (not present) in the
string distinctChars, it is concatenated to distinctChars.
● On execution of line 13, finally, the function returns a string (distinctChars) of distinct characters.
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