author | Puneeth Chaganti <punchagan@gmail.com> |
Wed, 21 Apr 2010 14:43:08 +0530 | |
changeset 95 | fddcfd83e4f0 |
child 96 | 3498d74ed615 |
permissions | -rw-r--r-- |
95
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
diff
changeset
|
1 |
* Data Types |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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changeset
|
2 |
*** Outline |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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3 |
***** Introduction |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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4 |
******* What are we going to do? |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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5 |
******* How are we going to do? |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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6 |
******* Arsenal Required |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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7 |
********* None |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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8 |
*** Script |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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9 |
Welcome friends. |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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10 |
|
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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11 |
In this tutorial we shall look at data types available in Python and |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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12 |
how to perform simple Input and Output operations. |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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13 |
for 'Numbers' we have: int, float, complex datatypes |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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14 |
for Text content we have strings. |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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changeset
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15 |
For conditional statements, 'Booleans'. |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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16 |
|
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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17 |
Now we shall look at Python Strings. |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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18 |
In python anything enclosed inside quotes(single or double) is a string |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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19 |
so |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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a = 'This is a string' |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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print a |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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b = "This too!" |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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print b |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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c = '''This one too!''' |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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print c |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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26 |
d = """And one more.""" |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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27 |
print d |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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28 |
|
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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29 |
Similar to lists we covered earlier even string elements can be accessed |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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30 |
via index numbers starting from 0 |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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31 |
|
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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32 |
print a[0] |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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33 |
print a[5] |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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34 |
will |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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To access last element we can use a[-1] which is one of Pythons feature. |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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36 |
print a[-1] |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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|
37 |
len function works with the strings also as it does with the arrays and |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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returns length of the string. |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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39 |
|
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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40 |
One thing to notice about the string variables is that they are |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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41 |
immutable, that is |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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42 |
a[0] = 't' |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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43 |
will throw an error |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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|
44 |
|
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
diff
changeset
|
45 |
Some of methods available for string are: |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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46 |
a.startswith('Thi') |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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returns true if initial of the string is same |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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48 |
similarly there is endswith |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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49 |
a.endswith('ING') |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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50 |
a.upper() returns a string with all letters capitalized. |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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51 |
and a.lower() returns a string with all smaller case letters. |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
diff
changeset
|
52 |
As we have seen earlier use of split function, it returns the list after |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
diff
changeset
|
53 |
splitting the string, so |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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changeset
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54 |
a.split() |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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55 |
will give list with three elements. |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
diff
changeset
|
56 |
we also have 'join' function, which does the opposite of what |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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changeset
|
57 |
split does. |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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58 |
''.join(['a','b','c']) will return a joined string of the list we pass |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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59 |
to it. Since join is performed on '' that is empty string we get 'abc' |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
diff
changeset
|
60 |
if we do something like |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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61 |
'-'.join(['a','b','c']) |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
diff
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|
62 |
|
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
diff
changeset
|
63 |
we come to the end of this tutorial on introduction of Data types in |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
diff
changeset
|
64 |
Python. In this tutorial we have learnt what are supported data types, |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
diff
changeset
|
65 |
supported operations and performing simple IO operations in Python. |
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
diff
changeset
|
66 |
|
fddcfd83e4f0
Split data-files.org into numbers and strings.
Puneeth Chaganti <punchagan@gmail.com>
parents:
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|
67 |
*** Notes |