Python Scripting - Week 6

Question 1

What is namespace in python ?

Answer 1

It means scope of an variable where it belongs to ?

Question 2

How many name spaces in python ?

Answer 2

LEGB
Local - Local Scope
Enclosed - Function within Function,Nested Function
Global - A variable which have scope everywhere.
Built-ins - Builtin Functions

It corresponds to function

Question 3

How to print python builtins ?

Answer 3

dir(__builtins__)
Builtins are loaded on startup bydefault,when python program starts

Question 4

How to get help of builtin ?

Answer 4

help(ArithmeticError)

Question 5

How to get type of builtin ?

Answer 5

typer(ArithmeticError)

Question 6

How to print globals ?

Answer 6

globals()

Question 7

How to print the all globals in table format ?

Answer 7

whos

Question 8

In which namespace should every varaible is stored ?

Answer 8

Every variable is stored in the globals

Question 9

How python searches for variable, what is rthe thumb rule ?

Answer 9

Python follows LEGB rule ?
Local
Enclosed
Global
Builtin

Question 10

How to return multiple variables in function ?

Answer 10

Use comma seperator

Question 11

What is returned by-default by function, when we return multiple values from function ?

Answer 11

Tuple is returned by default
Multiple Values packed in tuple by-default

Question 12

How to return list from function ?

Answer 12

Enclose the return values in list then return
return [“This is a string”, “another one”,10]

Question 13

What is unpacking ?

Answer 13

Returning multiple values , and collect them in multiple variables .Most important thing is no. of of return values & collecting variables should be in same
def create_something():
return [“This is a string”, “another one”,10]
a,b,c=create_something()
print(a,b,c)

Question 14

What is the default return type of function ?

Answer 14

If no return statement is given, then function Returns
NoneType

Question 15

What is EGB ?

Answer 15

EGB is an namespace
E - Enclosed
G- Global
B- Builtin

Question 16

How many types of arguments in a function ?

Answer 16

They are of two types:
1. Positional arguments - just listed variable names x,y,z
2. Keyword arguments - variable with an assignment operator a=10

Question 17

Where to get keyword arguments ?

Answer 17

All keyword arguments must follow all position arguments
def xyz(a,b,c,d=10)

Question 18

What is the benefit of named variable in function argument ?

Answer 18

It is beneficial while calling a function, you do not need to remember the position of the argument, you can use it by name in any order

Question 19

Write a function with return combine named variable arguments ?

Answer 19

def combineName(firstName='',lastName=''):
    return firstName+" "+lastName
print(combineName(lastName='Kumar',firstName='Hemant'))

Question 20

What are Document String in function ?

Answer 20

Doct strings allow us to add some text info to function, when we hover on function it shows that text, it is very helpful to know about the function.

Question 21

How to add doct string to an function ?

Answer 21

Doct can be added in trtiple quotes
~~~
def combineName(firstName=’‘,lastName=’’):
“"”This function Combine Names “””
return firstName+” “+lastName
~~~

Question 22

How to make iter ?

Answer 22

a = iter(‘Hello’)
next(a)

Question 23

What is lazy iteration ?

Answer 23

we have to use yield keyword,yield keyword is used to make generator object.

def gen_count_by_twos():
    num=0
    while True:
        yield num
        num+=2
for i in gen_count_by_twos():
    print(i)
    if i>20:
        break

Question 24

What is exhaustion of generator ?

Answer 24

When it finishes itertation ?

Question 25

How to make a generator object of 100 numbers ?

Answer 25

We have to use list comprehension
count_100=(i for i in range(100))
for i in count_100:
print(i)

Question 26

Can we use generators multiple times ?

Answer 26

No , generators can only be used once, they are exhausted when iteration is finished.
You have to recreate them to use

Question 27

What is the keyword argument in print function ?

Answer 27

end=”” is the keyword argument in print method()
print function will always append a \n to the end of the string ,This is so when you make your next call to print(), it will print on the next line.

Question 28

How to make a generator of 100 numbers using comprehension ?

Answer 28

We have to use parenthesis for generator comprehension.
count_100=(i for i in range(100))
type(count_100

Question 29

Is range() object is an generator, iterator or sequence ?

Answer 29

Its a sequence.

Question 30

How to get memory size of object ?

Answer 30

import sys
sys.getsizeof(count_100)