tuples in python

-
Sorry guys i am let because my External exam are currently runing but i will provide lesson every day to you from now
  


  
* Tuples *
 
Tuples:-
A tuple is a sequence of immutable (unchange able) Python objects. Tuples are sequences, just like lists. The differences between tuples and lists are, the tuples cannot be changed unlike lists and tuples use parentheses, whereas lists use square brackets.
Creating a tuple is as simple as putting different comma-separated values. Optionally you can put these comma-separated values between parentheses also.

Example:-

tup1 = ('physics', 'chemistry', 1997, 2000);
tup2 = (1, 2, 3, 4, 5 );
tup3 = "a", "b", "c", "d";
 

Accessing Values in Tuples

To access values in tuple, use the square brackets for slicing along with the index or indices to obtain value available at that index.

For example −

tup1 = ('physics', 'chemistry', 1997, 2000); 
tup2 = (1, 2, 3, 4, 5, 6, 7 );  
print "tup1[0]: ", tup1[0]; 
print "tup2[1:5]: ", tup2[1:5];
 
Output :−
tup1[0]: physics
tup2[1:5]: [2, 3, 4, 5]

Updating Tuples

Tuples are immutable which means you cannot update or change the values of tuple elements. You are able to take portions of existing tuples to create new tuples as the following
 example demonstrates −


tup1 = (12, 34.56); 
tup2 = ('abc', 'xyz');

# Following action is not valid for tuples
# tup1[0] = 100;

# So let's create a new tuple as follows
tup3 = tup1 + tup2;
print tup3;
 
Output :−
(12, 34.56, 'abc', 'xyz')
 

Delete Tuple Elements

Removing individual tuple elements is not possible. There is, of course, nothing wrong with putting together another tuple with the undesired elements discarded.
To explicitly remove an entire tuple, just use the del statement. For example −

tup = ('physics', 'chemistry', 1997, 2000);  
print tup; 
del tup;  
print "After deleting tup : ";  
print tup;

This produces the following result. Note an exception raised, this is because after del tup tuple does not exist any more −
Ouput:-

('physics', 'chemistry', 1997, 2000)
After deleting tup :
Traceback (most recent call last):
           File "test.py", line 9, in <module>
                        print tup;
NameError: name 'tup' is not defined 
 

Basic Tuples Operations

Tuples respond to the + and * operators much like strings; they mean concatenation and repetition here too, except that the result is a new tuple, not a string.
In fact, tuples respond to all of the general sequence operations we used on strings in the prior chapter −
Python Expression Results Description
len((1, 2, 3)) 3 Length
(1, 2, 3) + (4, 5, 6) (1, 2, 3, 4, 5, 6) Concatenation
('Hi!',) * 4 ('Hi!', 'Hi!', 'Hi!', 'Hi!') Repetition
3 in (1, 2, 3) True Membership
for x in (1, 2, 3): print x, 1 2 3 Iteration
 

Indexing, Slicing, and Matrixes

Because tuples are sequences, indexing and slicing work the same way for tuples as they do for strings. Assuming following input −
L = ('spam', 'Spam', 'SPAM!')

Python Expression Results Description
L[2] 'SPAM!' Offsets start at zero
L[-2] 'Spam' Negative: count from the right
L[1:] ['Spam', 'SPAM!'] Slicing fetches sections

No Enclosing Delimiters

Any set of multiple objects, comma-separated, written without identifying symbols, i.e., brackets for lists, parentheses for tuples, etc., default to tuples, as indicated in these short
examples −


print 'abc', -4.24e93, 18+6.6j, 'xyz';
x, y = 1, 2;
print "Value of x , y : ", x,y;
 
Output : −

abc -4.24e+93 (18+6.6j) xyz
Value of x , y : 1 2
 

Built-in Tuple Functions

Python includes the following tuple functions −
Sr.No. Function with Description
1 cmp(tuple1, tuple2) Compares elements of both tuples.
2 len(tuple) Gives the total length of the tuple.
3 max(tuple) Returns item from the tuple with max value.
4 min(tuple) Returns item from the tuple with min value.
5 tuple(seq) Converts a list into tuple.
 ##################################################################################
in next lecture we will discuss about the List
for the blog thanks the * www.tutorialspoint.com *  


*books that help you to learn python *







 

  



I WILL SUGGEST  FIRST BOOK STRONGLY 
































Comments











Post a Comment



















Popular posts from this blog









Python Class and Objects






-














Image







Python Class and Objects What is class and object ? class :-  it is a structure which is used to where you put your data and any function that you want  for example : if you buy any house it is full empty in that room you see a kitchen, bedroom, hall this we example of class and when you put something in the house like T.V, A.C, Sofa more.. it means you put some value on the class . in above left image is a class with no value and in right their is a class with value  for understanding replace class with hall and value with (TV, Sofa etc..) How we can implement class and object in python ? To create a class, use the keyword  class : Example : class   Room :         total_sofa =  5 this way we create class in python. How we can access class variable (ex: total_sofa ) value ? Answer: by using "object" let me explain don't get confuse  To create a object, we use : syntax : object = class_name() Create an object named p1, and print the value of total_sofa: Example : p1 = Room








Read more










exception handling in python






-














Image







  EXCEPTION HANDLING IN PYTHON    A Python program terminates as soon as it encounters an error. In  Python, an error can be a syntax error or an exception. In this article,  you will see what an exception is and how it differs from a syntax  error. After that, you will learn about raising exceptions and making  assertions. Then, you’ll finish with a demonstration of the try and  except block.     Exceptions versus Syntax Errors  Syntax errors occur when the parser detects an incorrect statement. Observe the following example:   >>> print ( 0 / 0 ))    File " <stdin> " , line 1      print (  0  /  0  ))                    ^  SyntaxError :  invalid syntax       The arrow indicates where the parser ran into the syntax error . In this example, there was one bracket too many. Remove it and run your code again:    >>> print ( 0 / 0 )  Traceback (most recent call last):    File " <stdin> " , line 1 , in <module>  ZeroDivisionError : int








Read more










Fibonacci series in python






-














Image







Fibonacci Series Fibonacci series is 0,1,1,2,3,5,8,13,21,34,............,infinity . It is a sequence of number which follow some type of algorithm the alogrithm is  let  i = index position  a = it is a array of number  so to find a[i+1] = a[i]+a[i-1]. Note : fibonacci series always start with 0 and 1 and goes upto infinity.you can't start with your own values. Explanation: 1. 0 and 1 in starting is default values  2. if we go further the algorithm start adding previous 2 value and the answer is the next value.     as you can see the previous two value is 0 and 1 after adding both we get 1 as our 3rd value.     after that adding 1 and 1 we get our 4th value as 2 this entire cycle goes like this only. i think you get better understanding about fibonacci series we move further on coding of fibo  in python: Flowchart: coding: without recursion function: def  fibonacci(n):      a =  0      b =  1      if  n < =  0 :          print ( "Incorrect input" )      else :          








Read more