What is the index operator in python?
Index operator
The index operator (Python uses square brackets to enclose the index) selects a single character from a string.
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In strings, the characters are accessed by their position or index.
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In lists and tuples, items are accessed by their position or index.
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Characters are indexed left to right from position ‘0’ to position ‘13’. Positions are also named from right to left using negative numbers, where
-1is the rightmost index and so on.
Example
List = [10,20,'apple',30,'mango',40] tuple = ['hello','pi','value','is',3.14]
Code
a="hello students"b=['hello','pi','value','is',3.14]c=('hello','pi','value','is',3.14)l=a[2]print(l)lastcher=a[-1]print(lastcher)print(b[2])print(b[3-6])print(b[-2])print(c[0])print(c[-1])print(c[2-4])print(b[7-8])
count()
The count method returns the number of times the argument occurred in the string/list upon which the method was used.
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We cannot count how many times integer 2 occurred, but we can count how many times string ‘2’ occurred.
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The count method works for lists too.
Code
a="I have had an apple on my desk before!"print(a.count("e"))print(a.count("ha"))z=['atoms',4,'neutron',6,'proton',4,'electron',4,'electron','atoms']print(z.count("4"))print(z.count(4))print(z.count("a"))print(z.count("electron"))