Question

Question 5 Python Language

1. What is the output of the following code ? (2 points)

a, b = 0, 1

while b < 10: print b

a, b = b, a+b

B. Explain List Comprehension (2 points)

Given v = [1 3 5]

w = [ [2*x, x**2] for x in v] What is the content of w?

c. What is tuple ?   What is the difference between tuple and list ? (2 points)

D. What is a module ?   What is the role of     all    ? (2 points)

Answer 1

A.The screenshot of the program and the output generated is attached for reference:

The output:

Here the initial value of a is 0 and b is 1.

In the while loop value of b is passed to a and the sum of a+b (here a value equals to intial value before changing to value of b) is stored in b.

The while loop executes and prints value in b until the condition is violated.

B.List comprehension can be defined as a deadly useful method in python to create a list.

There are three ways to insert values to list:

1)for loop         2)map() function           3)list comprehension

What list comprehension offers is a declarative elegent syntax .Using list comprehension we just needs to focus on adding more values to the list , while the construction of list will be handled by python.

The contents in list w is [[2, 1], [6, 9], [10, 25]]

this is because for every value in list v value x changes and adds a new nested list in w with values 2*x and x**2

The screenshot of the program and output generated is attached for reference:

The output generated by this program:

C.Tuple is a datatype which is immutable in nature.

The difference between list and tuple are:

1. The tuple datatype is immutable in nature while list is mutable datatype.
2. List is declared using square brackets "[ ]" while tuples are declared using paranthesis "( )"
3. Example for a list : l1 = [1,2,3,4] and example for a tuple: t1 =(1,2,3,4)

D.Modules are collection of functions which can be loaded into our program when needed.

Modules reduces the complexity and length of the overall program

In python modules are loaded into a program using from and import statement.

Example: from module_name import * , loads all the functions in that module

The role of all denoted by (*) is used to denote all the functions included in that module and so using it allows us to make use of all that module functions in our program.

Hope it helps!!!