Python Q&A
Python Q&A - Part5
179) What is encapsulation?
Answer: Encapsulation is packing of data and functions. It hides the implementation details of a class from other objects
180) What is polymorphism?
Answer: It is using an entity(operator, function or object) in different ways in different scenarios
181) What is method overriding?
Answer: The ability of child class to change the implementation of method provided by parent class
182) What is PYTHONHOME environment variable?
Answer: It is used to set the default location of the standard Python libraries
183) How will you convert a string to an object
Answer: eval(string)
184) What is the output of the following?
lst=[2,3,1]
lst.sort()
print(lst[2])
Answer: 3
185) What is the code to print the largest number of the following list
lst=[25,30,20]
Answer: print(max(lst))
186) What is monkey patching?
Answer: It is dynamic modification of a class or module at run-time
187) How do you create empty class?
Answer:
class myclass:
pass
188) How do you create object of empty class?
Answer: x=myclass()
189) x=’abcd’
print(x[::-1])
Answer: dcba
190) Write code to check if ‘noon’ is palindrome
Answer:
x=’noon’
y=x[::-1]
if x==y:
print(“Palindrome”)
else:
print(“Not Palindrome”)
191) Write the code to find how many numbers are there in the string str = ‘Python1Test2’
Answer:
y=0
for x in str:
if x.isnumeric():
y=y+1
print(y)
192) What is a framework?
Answer: A framework is a code library that provides reusable code or extensions for common operations.
193) What is the output of following code?
def fn(x):
if x == 0:
return 1
else:
return x*fn(x-1)
print(fn(5))
Answer: 120
Explanation: (5*4*3*2*1)
194) Name some of the frameworks of Python
Answer: Flask, Django, Pyramid, Tornado
195) print(‘ Hello ‘.strip())
Answer: Hello
Explanation: Removes leading, trailing white spaces
196) What is the output of the following?
str=’hello’
print(str.swapcase())
Answer: HELLO
197) Add 3 before 4 in lst [1,2,4]
Answer: lst.insert(2,3)
198) How do you reverse a list
Answer: list.reverse()
199) Write code to sort alphabetically
str=’d e c a b’
Answer:
str=’d e c a b’
str1=[s.lower() for s in str.split()]
str1.sort()
for x in str1:
print(x)
200) Are strings immutable?
Answer: Yes
201) What is Scikit-learn?
Answer: It is a library containing tools for machine learning
202) What is Pylint?
Answer: Pylint analyses code without running it. It checks for errors and tries to enforce a coding standard and style
203) With which version of Python is Pylint compatible?
Answer: Pylint is compatible with versions greater than 2.7.0
204) What is Pychecker?
Answer: It is a tool for finding bugs in python source code
205) What is difference between Pylint and Pychecker?
Answer: Pylint checks for style issues while Pychecker don’t. Pylint does not import live modules while Pychecker does
206) What is a regular expression?
Answer: It is a special sequence of characters that help match or find other string or
207) Which module support regular expression?
Answer: re module
208) What is the output of the following code?
import re
str=’Python books’
x=re.search(‘^P’,str)
if x:
print(“Starts with P”)
else:
print(“Don’t start with P”)
Answer: Starts with P
209) What is output of the following code?
import re
str=’Books on Python’
x=re.findall(‘Python$’,str)
if x:
print(“Ends with Python”)
else:
print(“Don’t end with Python”)
Answer: Ends with Python
210) What is the output of the following?
import re
str = “Office opens at AM”
#x=re.findall(‘AM’,str)
x=re.sub(“AM”, “9AM”, str)
print(x)
Answer: Office opens at 9AM
211) What does \b mean with respect to regular expression:
Answer: Returns a match where the specified characters are at the beginning or at the end of a word
212) What is the output of the following?
import re
str = “Python is the trend”
x = re.search(r”\btr”, str)
print(x.span())
Answer: (14, 16)
Explanation:
(This means that the letters “tr” exists at the beginning of the word in the string str between positions 14 and 16)
(\b – Returns a match where the specified characters are at the beginning or at the end of a word)
213) What is output of the following?
import re
str = “Python is the trend”
x = re.search(r”\btr\w+”, str)
print(x.group())
Answer: trend
Explanation: (This returns the word where the letters exist)