strings.org
author Puneeth Chaganti <punchagan@gmail.com>
Wed, 21 Apr 2010 14:43:08 +0530
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permissions -rw-r--r--
Split data-files.org into numbers and strings.
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* Data Types
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*** Outline
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***** Introduction
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******* What are we going to do?
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******* How are we going to do?
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******* Arsenal Required
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********* None
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*** Script
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    Welcome friends. 
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    In this tutorial we shall look at data types available in Python and 
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    how to perform simple Input and Output operations. 
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    for 'Numbers' we have: int, float, complex datatypes
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    for Text content we have strings.
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    For conditional statements, 'Booleans'.
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    Now we shall look at Python Strings.
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    In python anything enclosed inside quotes(single or double) is a string
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    so 
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    a = 'This is a string'
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    print a
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    b = "This too!"
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    print b
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    c = '''This one too!'''
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    print c
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    d = """And one more."""
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    print d
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    Similar to lists we covered earlier even string elements can be accessed 
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    via index numbers starting from 0
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    print a[0]    
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    print a[5]
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    will 
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    To access last element we can use a[-1] which is one of Pythons feature.
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    print a[-1]
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    len function works with the strings also as it does with the arrays and 
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    returns length of the string.
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    One thing to notice about the string variables is that they are 
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    immutable, that is
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    a[0] = 't'
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    will throw an error
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    Some of methods available for string are:
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    a.startswith('Thi')
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    returns true if initial of the string is same
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    similarly there is endswith
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    a.endswith('ING')
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    a.upper() returns a string with all letters capitalized.
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    and a.lower() returns a string with all smaller case letters.
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    As we have seen earlier use of split function, it returns the list after
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    splitting the string, so
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    a.split()
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    will give list with three elements.
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    we also have 'join' function, which does the opposite of what
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    split does. 
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    ''.join(['a','b','c']) will return a joined string of the list we pass
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    to it. Since join is performed on '' that is empty string we get 'abc'
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    if we do something like
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    '-'.join(['a','b','c'])
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    we come to the end of this tutorial on introduction of Data types in
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    Python. In this tutorial we have learnt what are supported data types, 
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    supported operations and performing simple IO operations in Python.
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*** Notes