SEES: comparison basic_python/intro.rst

equal deleted inserted replaced

-:8f43cab360aa
+:932a7a863120
-=====================
+============
-Basic Python Workshop
+Basic Python
-=====================
+============
 This document is intended to be handed out at the end of the workshop. It has
 been designed for Engineering students who are Python beginners and have basic
 programming skills. The focus is on basic numerics and plotting using Python.
 The system requirements:
 * Python - version 2.5.x or newer.
 * IPython
 * Text editor - scite, vim, emacs or whatever you are comfortable with.
-1. Introduction
+Introduction
-===============
+============
 The Python programming language was created by a dutch named Guido van Rossum.
 The idea of Python was conceived in December 1989. The name Python has nothing
 to do with the reptilian, but its been named after the 70s comedy series
 "Monty Python's Flying Circus", since it happens to be Guido's favourite
 Although, Python has one setback. Python is not fast as some of the compiled
 languages like C or C++. Yet, the amount of flexibility and power more than make
 up for this setback.
-1.1 The Python Interpreter
+The Python Interpreter
---------------------------
+======================
-1.1.1 The Interactive Interpreter
+The Interactive Interpreter
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
 Typing *python* at the shell prompt on any standard Unix/Gnu-Linux system and
 hitting the enter key fires up the Python 'Interactive Interpreter'. The Python
 interpreter is one of the most integral features of Python. The prompt obtained
 when the interactive interpreter is similar to what is shown below. The exact
 ::
 This example is to show that unlike in C or C++ there is no limit on the
 value of an integer.
-1.1.2 *ipython* - An enhanced interactive Python interpreter
+*ipython* - An enhanced interactive Python interpreter
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 The power and the importance of the interactive interpreter was the highlight
 of the previous section. This section provides insight into the enhanced
 interpreter with more advanced set of features called **ipython**. Entering
 *ipython* at the shell prompt fires up the interactive interpreter.
 ::
 In [4]: a = 6
 In [5]: a.
-a.__abs__           a.__divmod__        a.__index__         a.__neg__
+a.__abs__           a.__divmod__        a.__index__         a.__neg__          a.__rand__          a.__rmod__          a.__rxor__
-a.__rand__          a.__rmod__          a.__rxor__
+a.__add__           a.__doc__           a.__init__          a.__new__          a.__rdiv__          a.__rmul__          a.__setattr__
-a.__add__           a.__doc__           a.__init__          a.__new__
+a.__and__           a.__float__         a.__int__           a.__nonzero__      a.__rdivmod__       a.__ror__           a.__str__
-a.__rdiv__          a.__rmul__          a.__setattr__
+a.__class__         a.__floordiv__      a.__invert__        a.__oct__          a.__reduce__        a.__rpow__          a.__sub__
-a.__and__           a.__float__         a.__int__           a.__nonzero__
+a.__cmp__           a.__getattribute__  a.__long__          a.__or__           a.__reduce_ex__     a.__rrshift__       a.__truediv__
-a.__rdivmod__       a.__ror__           a.__str__
+a.__coerce__        a.__getnewargs__    a.__lshift__        a.__pos__          a.__repr__          a.__rshift__        a.__xor__
-a.__class__         a.__floordiv__      a.__invert__        a.__oct__
+a.__delattr__       a.__hash__          a.__mod__           a.__pow__          a.__rfloordiv__     a.__rsub__
-a.__reduce__        a.__rpow__          a.__sub__
+a.__div__           a.__hex__           a.__mul__           a.__radd__         a.__rlshift__       a.__rtruediv__
-a.__cmp__           a.__getattribute__  a.__long__          a.__or__
-a.__reduce_ex__     a.__rrshift__       a.__truediv__
-a.__coerce__        a.__getnewargs__    a.__lshift__        a.__pos__
-a.__repr__          a.__rshift__        a.__xor__
-a.__delattr__       a.__hash__          a.__mod__           a.__pow__
-a.__rfloordiv__     a.__rsub__
-a.__div__           a.__hex__           a.__mul__           a.__radd__
-a.__rlshift__       a.__rtruediv__
 In this example, we initialized 'a' (a variable - a concept that will be
 discussed in the subsequent sections.) to 6. In the next line when the *tab* key
 is pressed after typing '*a.*' ipython displays the set of all possible methods
 that are applicable on the object 'a' (an integer in this context). Ipython
 provides many such datatype specific features which will be presented in the
 further sections as and when the datatypes are introduced.
-1.2 Editing and running a python file
+Editing and running a python file
--------------------------------------
+=================================
-The
+The previous sections focused on the use of the interpreter to run python code.
+While the interpeter is an excellent tool to test simple solutions and
+experiment with small code snippets, its main disadvantage is that everything
+written in the interpreter is lost once its quit. Most of the times a program is
+used by people other than the author. So the programs have to be available in
+some form suitable for distribution, and hence they are written in files. This
+section will focus on editing and running python files. Start by opening a text
+editor ( it is recommended you choose one from the list at the top of this page ).
+In the editor type down python code and save the file with an extension **.py**
+(python files have an extension of .py). Once done with the editing, save the
+file and exit the editor.
+Let us look at a simple example of calculating the gcd of 2 numbers using Python:
+**Creating the first python script(file)**
+::
+$ emacs gcd.py
+def gcd(x,y):
+if x % y == 0:
+return y
+return gcd(y, x%y)
+print gcd(72, 92)
+To run the script, open the shell prompt, navigate to the directory that
+contains the python file and run `python <filename.py>` at the prompt ( in this
+case filename is gcd.py )
+**Running the python script**
+::
+$ python gcd.py
+4
+$
+Basic Datatypes and operators in Python
+=======================================

changeset 39	932a7a863120
parent 34	7a243a6d8625
child 40	ccdbbc094579