What is
Python?
Python is a
high-level, interpreted, interactive and object-oriented scripting language.
Python is designed to be highly readable. It uses English keywords frequently
where as other languages use punctuation, and it has fewer syntactical
constructions than other languages.
Name some
of the features of Python.
Following are some of
the salient features of python −
·
It supports functional and structured programming methods as well as
OOP.
·
It can be used as a scripting language or can be compiled to byte-code
for building large applications.
·
It provides very high-level dynamic data types and supports dynamic type
checking.
·
It supports automatic garbage collection.
·
It can be easily integrated with C, C++, COM, ActiveX, CORBA, and Java.
What is
the purpose of PYTHONPATH environment variable?
PYTHONPATH - It has a
role similar to PATH. This variable tells the Python interpreter where to
locate the module files imported into a program. It should include the Python
source library directory and the directories containing Python source code.
PYTHONPATH is sometimes preset by the Python installer.
What is
the purpose of PYTHONSTARTUP environment variable?
PYTHONSTARTUP - It
contains the path of an initialization file containing Python source code. It
is executed every time you start the interpreter. It is named as .pythonrc.py
in Unix and it contains commands that load utilities or modify PYTHONPATH.
What is
the purpose of PYTHONCASEOK environment variable?
PYTHONCASEOK − It is
used in Windows to instruct Python to find the first case-insensitive match in
an import statement. Set this variable to any value to activate it.
What is
the purpose of PYTHONHOME environment variable?
PYTHONHOME − It is an
alternative module search path. It is usually embedded in the PYTHONSTARTUP or
PYTHONPATH directories to make switching module libraries easy.
Is python
a case sensitive language?
Yes! Python is a case
sensitive programming language.
What are
the supported data types in Python?
Python has five
standard data types −
·
Numbers
·
String
·
List
·
Tuple
·
Dictionary
What is
the output of print str if str = 'Hello World!'?
It will print
complete string. Output would be Hello World!.
What is
the output of print str[0] if str = 'Hello World!'?
It will print first
character of the string. Output would be H.
What is
the output of print str[2:5] if str = 'Hello World!'?
It will print
characters starting from 3rd to 5th. Output would be llo.
What is
the output of print str[2:] if str = 'Hello World!'?
It will print
characters starting from 3rd character. Output would be llo World!.
What is
the output of print str * 2 if str = 'Hello World!'?
It will print string
two times. Output would be Hello World!Hello World!.
What is
the output of print str + "TEST" if str = 'Hello World!'?
It will print
concatenated string. Output would be Hello World!TEST.
What is
the output of print list if list = [ 'abcd', 786 , 2.23, 'john', 70.2 ]?
It will print
complete list. Output would be ['abcd', 786, 2.23, 'john', 70.200000000000003].
What is
the output of print list[0] if list = [ 'abcd', 786 , 2.23, 'john', 70.2 ]?
It will print first
element of the list. Output would be abcd.
What is
the output of print list[1:3] if list = [ 'abcd', 786 , 2.23, 'john', 70.2 ]?
It will print
elements starting from 2nd till 3rd. Output would be [786, 2.23].
What is
the output of print list[2:] if list = [ 'abcd', 786 , 2.23, 'john', 70.2 ]?
It will print
elements starting from 3rd element. Output would be [2.23, 'john',
70.200000000000003].
What is
the output of print tinylist * 2 if tinylist = [123, 'john']?
It will print list
two times. Output would be [123, 'john', 123, 'john'].
What is
the output of print list1 + list2, if list1 = [ 'abcd', 786 , 2.23, 'john',
70.2 ] and ist2 = [123, 'john']?
It will print
concatenated lists. Output would be ['abcd', 786, 2.23, 'john', 70.2, 123,
'john']
What are
tuples in Python?
A tuple is another
sequence data type that is similar to the list. A tuple consists of a number of
values separated by commas. Unlike lists, however, tuples are enclosed within
parentheses.
What is
the difference between tuples and lists in Python?
The main differences
between lists and tuples are − Lists are enclosed in brackets ( [ ] ) and their
elements and size can be changed, while tuples are enclosed in parentheses ( (
) ) and cannot be updated. Tuples can be thought of as read-only lists.
What is
the output of print tuple if tuple = ( 'abcd', 786 , 2.23, 'john', 70.2 )?
It will print
complete tuple. Output would be ('abcd', 786, 2.23, 'john',
70.200000000000003).
What is
the output of print tuple[0] if tuple = ( 'abcd', 786 , 2.23, 'john', 70.2 )?
It will print first
element of the tuple. Output would be abcd.
What is
the output of print tuple[1:3] if tuple = ( 'abcd', 786 , 2.23, 'john', 70.2 )?
It will print
elements starting from 2nd till 3rd. Output would be (786, 2.23).
What is
the output of print tuple[2:] if tuple = ( 'abcd', 786 , 2.23, 'john', 70.2 )?
It will print
elements starting from 3rd element. Output would be (2.23, 'john',
70.200000000000003).
What is
the output of print tinytuple * 2 if tinytuple = (123, 'john')?
It will print tuple
two times. Output would be (123, 'john', 123, 'john').
What is
the output of print tuple + tinytuple if tuple = ( 'abcd', 786 , 2.23, 'john',
70.2 ) and tinytuple = (123, 'john')?
It will print
concatenated tuples. Output would be ('abcd', 786, 2.23, 'john',
70.200000000000003, 123, 'john').
What are
Python's dictionaries?
Python's dictionaries
are kind of hash table type. They work like associative arrays or hashes found
in Perl and consist of key-value pairs. A dictionary key can be almost any
Python type, but are usually numbers or strings. Values, on the other hand, can
be any arbitrary Python object.
How will
you create a dictionary in python?
Dictionaries are enclosed
by curly braces ({ }) and values can be assigned and accessed using square
braces ([]).
dict = {}
dict['one'] = "This is one"
dict[2] = "This is two"
tinydict = {'name': 'john','code':6734, 'dept': 'sales'}
How will
you get all the keys from the dictionary?
Using
dictionary.keys() function, we can get all the keys from the dictionary object.
print dict.keys() # Prints all the keys
How will
you get all the values from the dictionary?
Using
dictionary.values() function, we can get all the values from the dictionary
object.
print dict.values() # Prints all the values
How will
you convert a string to an int in python?
int(x [,base]) -
Converts x to an integer. base specifies the base if x is a string.
How will
you convert a string to a long in python?
long(x [,base] ) -
Converts x to a long integer. base specifies the base if x is a string.
How will
you convert a string to a float in python?
float(x) − Converts x
to a floating-point number.
How will
you convert a object to a string in python?
str(x) − Converts
object x to a string representation.
How will
you convert a object to a regular expression in python?
repr(x) − Converts
object x to an expression string.
How will
you convert a String to an object in python?
eval(str) − Evaluates
a string and returns an object.
How will
you convert a string to a tuple in python?
tuple(s) − Converts s
to a tuple.
How will
you convert a string to a list in python?
list(s) − Converts s
to a list.
How will
you convert a string to a set in python?
set(s) − Converts s
to a set.
How will
you create a dictionary using tuples in python?
dict(d) − Creates a
dictionary. d must be a sequence of (key,value) tuples.
How will
you convert a string to a frozen set in python?
frozenset(s) −
Converts s to a frozen set.
How will
you convert an integer to a character in python?
chr(x) − Converts an
integer to a character.
How will
you convert an integer to an unicode character in python?
unichr(x) − Converts
an integer to a Unicode character.
How will
you convert a single character to its integer value in python?
ord(x) − Converts a
single character to its integer value.
How will
you convert an integer to hexadecimal string in python?
hex(x) − Converts an
integer to a hexadecimal string.
How will
you convert an integer to octal string in python?
oct(x) − Converts an
integer to an octal string.
What is
the purpose of ** operator?
** Exponent −
Performs exponential (power) calculation on operators. a**b = 10 to the power
20 if a = 10 and b = 20.
What is
the purpose of // operator?
// Floor Division −
The division of operands where the result is the quotient in which the digits
after the decimal point are removed.
What is
the purpose of is operator?
is − Evaluates to
true if the variables on either side of the operator point to the same object
and false otherwise. x is y, here is results in 1 if id(x) equals id(y).
What is
the purpose of not in operator?
not in − Evaluates to
true if it does not finds a variable in the specified sequence and false
otherwise. x not in y, here not in results in a 1 if x is not a member of
sequence y.
What is
the purpose break statement in python?
break statement −
Terminates the loop statement and transfers execution to the statement
immediately following the loop.
What is
the purpose continue statement in python?
continue statement −
Causes the loop to skip the remainder of its body and immediately retest its
condition prior to reiterating.
What is
the purpose pass statement in python?
pass statement − The
pass statement in Python is used when a statement is required syntactically but
you do not want any command or code to execute.
How can
you pick a random item from a list or tuple?
choice(seq) − Returns
a random item from a list, tuple, or string.
How can
you pick a random item from a range?
randrange ([start,]
stop [,step]) − returns a randomly selected element from range(start, stop,
step).
How can
you get a random number in python?
random() − returns a
random float r, such that 0 is less than or equal to r and r is less than 1.
How will
you set the starting value in generating random numbers?
seed([x]) − Sets the
integer starting value used in generating random numbers. Call this function
before calling any other random module function. Returns None.
How will
you randomizes the items of a list in place?
shuffle(lst) −
Randomizes the items of a list in place. Returns None.
How will
you capitalizes first letter of string?
capitalize() −
Capitalizes first letter of string.
How will
you check in a string that all characters are alphanumeric?
isalnum() − Returns
true if string has at least 1 character and all characters are alphanumeric and
false otherwise.
How will
you check in a string that all characters are digits?
isdigit() − Returns
true if string contains only digits and false otherwise.
How will
you check in a string that all characters are in lowercase?
islower() − Returns
true if string has at least 1 cased character and all cased characters are in
lowercase and false otherwise.
How will
you check in a string that all characters are numerics?
isnumeric() − Returns
true if a unicode string contains only numeric characters and false otherwise.
How will
you check in a string that all characters are whitespaces?
isspace() − Returns
true if string contains only whitespace characters and false otherwise.
How will
you check in a string that it is properly titlecased?
istitle() − Returns
true if string is properly "titlecased" and false otherwise.
How will
you check in a string that all characters are in uppercase?
isupper() − Returns
true if string has at least one cased character and all cased characters are in
uppercase and false otherwise.
How will
you merge elements in a sequence?
join(seq) − Merges
(concatenates) the string representations of elements in sequence seq into a
string, with separator string.
How will
you get the length of the string?
len(string) − Returns
the length of the string.
How will
you get a space-padded string with the original string left-justified to a
total of width columns?
ljust(width[,
fillchar]) − Returns a space-padded string with the original string
left-justified to a total of width columns.
How will
you convert a string to all lowercase?
lower() − Converts
all uppercase letters in string to lowercase.
How will
you remove all leading whitespace in string?
lstrip() − Removes
all leading whitespace in string.
How will
you get the max alphabetical character from the string?
max(str) − Returns
the max alphabetical character from the string str.
How will
you get the min alphabetical character from the string?
min(str) − Returns
the min alphabetical character from the string str.
How will
you replaces all occurrences of old substring in string with new string?
replace(old, new [,
max]) − Replaces all occurrences of old in string with new or at most max
occurrences if max given.
How will
you remove all leading and trailing whitespace in string?
strip([chars]) −
Performs both lstrip() and rstrip() on string.
How will
you change case for all letters in string?
swapcase() − Inverts
case for all letters in string.
How will
you get titlecased version of string?
title() − Returns
"titlecased" version of string, that is, all words begin with
uppercase and the rest are lowercase.
How will
you convert a string to all uppercase?
upper() − Converts
all lowercase letters in string to uppercase.
How will
you check in a string that all characters are decimal?
isdecimal() − Returns
true if a unicode string contains only decimal characters and false otherwise.
What is
the difference between del() and remove() methods of list?
To remove a list
element, you can use either the del statement if you know exactly which
element(s) you are deleting or the remove() method if you do not know.
What is
the output of len([1, 2, 3])?
3.
What is
the output of [1, 2, 3] + [4, 5, 6]?
[1, 2, 3, 4, 5, 6]
What is
the output of ['Hi!'] * 4?
['Hi!', 'Hi!', 'Hi!',
'Hi!']
What is
the output of 3 in [1, 2, 3]?
True
What is
the output of for x in [1, 2, 3]: print x?
1
2
3
What is
the output of L[2] if L = [1,2,3]?
3, Offsets start at
zero.
What is
the output of L[-2] if L = [1,2,3]?
1, Negative: count
from the right.
What is
the output of L[1:] if L = [1,2,3]?
2, 3, Slicing fetches
sections.
How will
you compare two lists?
cmp(list1, list2) −
Compares elements of both lists.
How will
you get the length of a list?
len(list) − Gives the
total length of the list.
How will
you get the max valued item of a list?
max(list) − Returns
item from the list with max value.
How will
you get the min valued item of a list?
min(list) − Returns
item from the list with min value.
How will
you get the index of an object in a list?
list.index(obj) −
Returns the lowest index in list that obj appears.
How will
you insert an object at given index in a list?
list.insert(index,
obj) − Inserts object obj into list at offset index.
How will
you remove last object from a list?
list.pop(obj=list[-1])
− Removes and returns last object or obj from list.
How will
you remove an object from a list?
list.remove(obj) −
Removes object obj from list.
How will
you reverse a list?
list.reverse() −
Reverses objects of list in place.
How will
you sort a list?
list.sort([func]) −
Sorts objects of list, use compare func if given.
What is
lambda function in python?
‘lambda’ is a keyword
in python which creates an anonymous function. Lambda does not contain block of
statements. It does not contain return statements.
What we
call a function which is incomplete version of a function?
Stub.
When a
function is defined then the system stores parameters and local variables
in an area of memory. What this memory is known as?
Stack.
A canvas
can have a foreground color? (Yes/No)
Yes.
Is Python
platform independent?
No
There are some
modules and functions in python that can only run on certain platforms.
Do you
think Python has a complier?
Yes
Yes it has a complier
which works automatically so we don’t notice the compiler of python.
What are
the applications of Python?
Django (Web framework
of Python).
2. Micro Frame work
such as Flask and Bottle.
3. Plone and Django
CMS for advanced content Management.
What is
the basic difference between Python version 2 and Python version 3?
Table below explains
the difference between Python version 2 and Python version 3.
|
S.No
|
Section
|
Python Version2
|
Python Version3
|
|
1.
|
Print Function
|
Print command can
be used without parentheses.
|
Python 3 needs
parentheses to print any string. It will raise error without parentheses.
|
|
2.
|
Unicode
|
ASCII str() types
and separate Unicode() but there is no byte type code in Python 2.
|
Unicode (utf-8) and
it has two byte classes −
|
|
3.
|
Exceptions
|
Python 2 accepts
both new and old notations of syntax.
|
Python 3 raises a
SyntaxError in turn when we don’t enclose the exception argument in
parentheses.
|
|
4.
|
Comparing
Unorderable
|
It does not raise
any error.
|
It raises
‘TypeError’ as warning if we try to compare unorderable types.
|
Which
programming Language is an implementation of Python programming language
designed to run on Java Platform?
Jython
(Jython is successor
of Jpython.)
Is there
any double data type in Python?
No
Is String
in Python are immutable? (Yes/No)
Yes.
Can True
= False be possible in Python?
No.
Which
module of python is used to apply the methods related to OS.?
OS.
When does
a new block begin in python?
A block begins when
the line is intended by 4 spaces.
Write a
function in python which detects whether the given two strings are
anagrams or not.
def check(a,b):
if(len(a)!=len(b)):
return False
else:
if(sorted(list(a)) == sorted(list(b))):
return True
else:
return False
Name the
python Library used for Machine learning.
Scikit-learn python
Library used for Machine learning
What does
pass operation do?
Pass indicates that
nothing is to be done i.e. it signifies a no operation.
Name the
tools which python uses to find bugs (if any).
Pylint and pychecker.
Write a
function to give the sum of all the numbers in list?
Sample list − (100,
200, 300, 400, 0, 500)
Expected output −
1500
Program for sum of
all the numbers in list is −
def sum(numbers):
total = 0
for num in numbers:
total+=num
print(''Sum of the numbers: '', total)
sum((100, 200, 300, 400, 0, 500))
We define a function
‘sum’ with numbers as parameter. The in for loop we store the sum of all the
values of list.
Write a
program in Python to reverse a string without using inbuilt function
reverse string?
Program to reverse a
string in given below −
def string_reverse(str1):
rev_str = ' '
index = len(str1) #defining index as length of string.
while(index>0):
rev_str = rev_str + str1[index-1]
index = index-1
return(rev_str)
print(string_reverse('1tniop'))
First we declare a
variable to store the reverse string. Then using while loop and indexing of
string (index is calculated by string length) we reverse the string. While loop
starts when index is greater than zero. Index is reduced to value 1 each time.
When index reaches zero we obtain the reverse of string.
Write a
program to test whether the number is in the defined range or not?
Program is −
def test_range(num):
if num in range(0, 101):
print(''%s is in range''%str(num))
else:
print(''%s is not in range''%str(num))
Output −
test_range(101)
101 is not in the
range
To test any number in
a particular range we make use of the method ‘if..in’ and else condition.
Write a
program to calculate number of uppercase letters and number of lower case
letters?
Test on String: ''Tutorials
POINT''
Program is −
def string_test(s):
a = { ''Lower_Case'':0 , ''Upper_Case'':0} #intiail count of lower and upper
for ch in s: #for loop
if(ch.islower()): #if-elif-else condition
a[''Lower_Case''] = a[''Lower_Case''] + 1
elif(ch.isupper()):
a[''Upper_Case''] = a [''Upper_Case''] + 1
else:
pass
print(''String in testing is: '',s) #printing the statements.
print(''Number of Lower Case characters in String: '',a[''Lower_Case''])
print(''Number of Upper Case characters in String: '',a[''Upper_Case''])
Output −
string_test(''Tutorials
POINT'')
String in testing is:
Tutorials POINT
Number of Lower Case
characters in String: 8
Number of Upper Case
characters in String: 6
We make use of the
methods .islower() and .isupper(). We initialise the count for lower and upper.
Using if and else condition we calculate total number of lower and upper case
characters.
No comments:
Post a Comment