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*Script
*Hello and welcome to this tutorial on Basic Python using Python.
This tutorial formally introduces Python as a language . Through this tutorial we will be able to understand Basic Data types like number , Boolean and strings .Some basic operators , simple input/output and basic conditional flow .
In numbers Python supports three kinds of data types ,
floats,integers and complex numbers
An integer can be defined as follows :
a=13
This make a an integer variable with value 13 .
You can also type 9 around 20 times
a=99999999999999999999999 . as you can see Python does not have a limit on how long an integer has to be . Isn't that great .
Now will try a float.
let's type
p=3.141592 if you type out p now you will notice that it is not absolutely equal to p you typed in . The reason for that is how a computer saves decimal values .
Apart from integer and float, Python has an in-built support for complex numbers. Now we try to assign a complex value to a variable .
Type:
c = 3+4j
As you can see ,the notation for complex numbers is similar to the one used in electric engineering.
We will now try some operations on complex numbers . First we will try to get the absolute value of the complex number . For this we will use the abs built in function . For this do :
abs in parenthesis c .
Do get the imaginary part of c you can do :
c.imag
and similarly for real part do :
c.real
Python also has Boolean as a built-in type .
Try it out just type ..
t=True , note that T in true is capitalized .
You can apply different Boolean operations on t now for example :
f=not t , this saves the value of not t that is False in f.
We can apply other operators like or and and ,
f or t gives us the value True while
f and t gives us the value false.
You can use parenthesis for precedence ,
Lets write some piece of code to check this out .
a=False
b=True
c=True
To check how precedence changes with parenthesis . We will try two expressions and their evaluation.
do
(a and b) or c
This expression gives the value True
where as the expression a and (b or c) gives the value False .
Now we will have a look at strings
type
w="hello"
w is now a string variable with the value "hello"
printing out w[0] + w[2] + w[-1] gives hlo if you notice the expression for accessing characters of a string is similar to lists .
Also functions like len work with strings just like the way they did with lists
Now lets try changing a character in the string in the same way we change lists .
type :
w[0]='Capital H'
oops this gives us a Type Error . Why? Because string are immutable . You can change a string simply by assigning a new element to it . This and some other features specific to string processing make string a different kind of data structure than lists .
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