Python Strings.pptx

Python Strings.pptx

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  M Vishnuvardhan String String isbasically represents sequence of characters. Technically string is a sequence of Unicode characters in Python. Strings are written in single or double quotes. Strings in Python are immutable i.e., modifying the string is not possible Eg: name='Python’ or name= "Python". Python allows to create multi line strings using ‘’’ or “”” Eg: msg = """ Python is a Object oriented Language ""“ : msg = ‘’’ Python is a Object oriented Language ‘’’
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  M Vishnuvardhan Accessing charsin String Individual characters of a string can be accessed using indexing. Index is a integer number representing the position of character in the string it starts from 0 and ends at n-1 (n-length) Eg: name= "Python". print(name[0]) #returns P print(name[2]) #returns t print(name[7]) # index error occurs Note: Python allows negative indexing on strings. Negative index starts at -1 and go p to –n. print(name[-1)) #prints n
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  M Vishnuvardhan String –Slicing Slicing operator (:) is used to get range of indexes. When specifying a range, the return value will be a new string with the specified items. Syntax stringName [ start : end ] # start is inclusive and end is exclusive Eg: name= "Programming" name[2:5] # returns ogr If start is skipped then returns items from beginning, If end is skipped then returns items till end .Slicing allows negative indexing also name[-6:-3] # returns amm -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 P r o g r a m m i n g 0 1 2 3 4 5 6 7 8 9 10
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  M Vishnuvardhan String –Advanced Slicing Syntax stringName [ start : end: step ] # start is inclusive and end is exclusive and step is increment Eg: name= "Programming« [low:high:+ve] – normal order name[2:10:2] # returns ormi [high:low:-ve] – reverse order name[10:2:-1] # returns gnimmarg name[::1] # returns Programming name[::-1] # returns gnimmargorP -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 P r o g r a m m i n g 0 1 2 3 4 5 6 7 8 9 10
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  M Vishnuvardhan String –Basic Operations Python Expression Results Description len(“Python”) 6 Length “Python” + “Program” “PythonProgram” Concatenation Py* 4 “PyPyPy” Repetition y in “Python” True Membership for x in “Python”: print x P y t h o n Iteration
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  M Vishnuvardhan String methods MethodDescription count() Returns the number of times a specified value occurs in a string find() Searches the string for a specified value and returns the position of where it was found format() Formats specified values in a string index() Searches the string for a specified value and returns the position of where it was found isalnum() Returns True if all characters in the string are alphanumeric isalpha() Returns True if all characters in the string are in the alphabet isdecimal() Returns True if all characters in the string are decimals isdigit() Returns True if all characters in the string are digits islower() Returns True if all characters in the string are lower case
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  M Vishnuvardhan String methods MethodDescription isnumeric() Returns True if all characters in the string are numeric isupper() Returns True if all characters in the string are upper case join() Converts the elements of an iterable into a string lower() Converts a string into lower case replace() Returns a string where a specified value is replaced with a specified value split() Splits the string at the specified separator, and returns a list strip() Returns a trimmed version of the string title() Converts the first character of each word to upper case upper() Converts a string into upper case
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  M Vishnuvardhan String Formatting format()method allows you to format selected parts of a string. It takes the passed arguments, formats them, and places them in the string where the placeholders {} are: Syntax: string.format(value1, value2...) The placeholders can be identified using named indexes {price}, numbered indexes {0}, or even empty placeholders {}. Eg: txt1 = "Python {name}, is {ver}".format(name = "Language", ver = 3.10) txt2 = "Python {0}, is {1}".format("Language",3.10) txt3 = "Python {}, is {}".format("Language",3.10)
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  M Vishnuvardhan String EscapeSequences Code Result ' Single Quote Backslash n New Line r Carriage Return t Tab b Backspace f Form Feed ooo Octal value xhh Hex value
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  M Vishnuvardhan