Python Interview Questions and Answers Set 1

1. What type of a language is python? Interpreted or Compiled?

Python is an interpreted, interactive, object­oriented programming language.

Python is an interpreted language, as opposed to a compiled one, though the distinction can be blurry because of the presence of the bytecode compiler. This means that source files can be run directly without explicitly creating an executable which is then run.

2. What do you mean by python being an “interpreted language”?

An interpreted languageis a programming language for which most of its implementations execute instructions directly, without previously compiling a program into machine­languageinstructions. In context of Python, it means that Python program runs directly from the source code.

3. What is python’s standard way of identifying a block of code?

Please provide an example implementation of a function called “my_func” that returns the square of a given variable “x”. (Continues from previous question)

Indentation.

def my_func(x):

return x ** 2

4. Is python statically typed or dynamically typed?

Dynamic.

In a statically typed language, the type of variables must be known (and usually declared) at the point at which it is used. Attempting to use it will be an error. In a dynamically typed language, objects still have a type, but it is determined at runtime. You are free to bind names (variables) to different objects with a different type. So long as you only perform operations valid for the type the interpreter doesn’t care what type they actually are.

5. Is python strongly typed or weakly typed language?

Strong.

In a weakly typed language a compiler / interpreter will sometimes change the type of a variable. For example, in some languages (like Java Script) you can add strings to numbers ‘x’ + 3 becomes ‘x3′. This can be a problem because if you have made a mistake in your program, instead of raising an exception execution will continue but your variables now have wrong and unexpected values. In a strongly typed language (like Python) you can’t perform operations inappropriate to the type of the object ­ attempting to add numbers to strings will fail. Problems like these are easier to diagnose because the exception is raised at the point where the error occurs rather than at some other, potentially far removed, place.

Create a unicode string in python with the string “This is a test string”? Ans.some_variable =u’This is a test string’ (or)

some_variable =u”This is a test string”

6. What is the python syntax for switch case statements?

Python doesn’t support switch­case statements. You can use if­else statements for this purpose.

7. What is a lambda statement? Provide an example.

A lambda statement is used to create new function objects and then return them at runtime.

Example:

my_func =lambda x:x**2

Creates a function called my_func that returns the square of the argument passed.

8. What are the rules for local and global variables in Python?

If a variable is defined outside function then it is implicitly global.If variable is assigned new value inside the function means it is local.If we want to make it global we need to explicitly define it as global. Variable referenced inside the function are implicit global.

9. What is the output of the following program?

#!/usr/bin/python

deffun1(a):

print(‘a:’,)a

a=33;

print’local a: ‘,a

=100 fun1(a)

Print(‘a outside fun1:’,a)

Output:   a:100   local a:33

   an outside fun1:100


10.What is the output of the following program?

deffoo(x,y):

global a=42 x,y =y,x b =33 b =17 c =100

print(a,b,x,y)

a,b,x,y =1,15,3,4

foo(17,4)

print(a,b,x,y)

Output:

42 17 4 17

42 15 3 4