Chapter 3 : "PYTHON" (STRING'S)

Chapter 3

                                 STRING'S

String is a data type in Python. String is a sequence of characters enclosed in quotes .We can primarily, write a string in these three ways

1. Single quoted strings   (a = "Harry")

2. Double quoted strings (b = "Harry")

3. Trible quoted Strings  (c = '!' Harry")

String Slicing:

                                 A String in Python can be sliced for getting a part of the string .

Consider the following "string" :

name= "[Harry]" => length = 5 

            0 1 2 3 4

        (-5)(-4)(-3)(-2) (-1) 

                                The index in a string starts from 0 to (length-1) in Python. In order to slice a string, we use the following syntax:

• sl = name [int_start:int_end](  first inder included > cast index is not included) 
•    sl [0:3] returns "Har" → Charaders from 0 la 3 
• sl[1:3] returns "ar^ prime - chacalins from 1 to 3 

Negative Indices: Negative Indices can also be  used as shown in the figure above. -1 corresponds to the (length-1) index, -2 (length -2)

Slicing with skip value :      

          We can provide a skip value as a part of our slice like this:                              1.Word="amaging "

2.word [1:6:2] = 'man'

Other advanced slicing techniques:

 word = " amazing" 

word [7] → word [0.7] → 'amazing!

String functions :

Some of the mostly used functions to perform operations on or manipulate strings are:

1. Len () function → This function returns the length of the string

*Ten ("Harry") → returns 5

2 . String ends with (  r r y)   → This function tells whither the variable string ends with the string "rry" or not if string is "harry", it returns true for "rry" since Harry ends with rry .

3 . String Count (c) → Counts the total number of occurence of any character

4 . siring capitalize() → This function capitalizes the first character of a given string.

5. string find (word)  →This function finds a word and returns the index of first occurence of that word in the string.

6. string replace (oldword, new word)→ This function replaces the old word with new word in String

7 . Escape Sequence Characters → Sequence of characters after backslash"\" (Escape Seq characters). Escape sequence character comprises of more than one characters but represents one character when used  within the strings. 

Examples \n \t,