10 Questions, 10 Minutes – 5/100

1. What if you want to toggle case for a Python string?

We have the swapcase() method from the str class to do just that. 1. >>> ‘AyuShi’.swapcase()

‘aYUsHI’

2. Write code to print only upto the letter t.

I love Python

>>> i=0
>>> while s[i]!=’t’:
print(s[i],end=’’) 4. i+=1
I love Py

3. What is recursion?

Whenafunctionmakesacalltoitself,itistermed recursion. Butthen,in order for it to avoid forming an infinite loop, we must have a base condition.

Let’s take an example.

>>> def facto(n): 
if n==1: return 1
return n*facto(n-1)
>>> facto(4)

4. What is a function?

When we want to execute a sequence of statements, we can give it a name. Let’s define a function to take two numbers and return the greater number.

>>> def greater(a,b): 
return a is a>b else b

5. Explain Python List Comprehension.

The list comprehension in python is a way to declare a list in one line of code. Let’s take a look at one such example.

>>> [i for i in range(1,11,2)] [1, 3, 5, 7, 9] 
>>> [i*2 for i in range(1,11,2)] [2, 6, 10, 14, 18]

6. How do you get all values from a Python dictionary?

We saw previously, to get all keys from a dictionary, we make a call to the keys() method. Similarly, for values, we use the method values().

 >>> 'd' in {'a':1,'b':2,'c':3,'d':4}.values()  
False
 >>> 4 in {'a':1,'b':2,'c':3,'d':4}.values()  
True

7. What is the difference between remove() function and del statement?

You can use the remove() function to delete a specific object in the list.

If you want to delete an object at a specific location (index) in the list, you can either use del or pop.

Note: You don’t need to import any extra module to use these functions for removing an element from the list.

We cannot use these methods with a tuple because the tuple is different from the list.


8. How to remove leading whitespaces from a string in the Python?

To remove leading characters from a string, we can use lstrip() function. It is Python string function which takes an optional char type parameter. If a parameter is provided, it removes the character. Otherwise, it removes all the leading spaces from the string.

string = "  javatpoint "   
string2 = "    javatpoint        "  
print(string)  
print(string2)  
print("After stripping all leading whitespaces:")  
print(string.lstrip())  
print(string2.lstrip())  


9. Why do we use join() function in Python?

A. The join() is defined as a string method which returns a string value. It is concatenated with the elements of an iterable. It provides a flexible way to concatenate the strings. See an example below.

str = "Rohan"  
str2 = "ab"  
# Calling function    
str2 = str.join(str2)    
# Displaying result    
print(str2)  
Output:
aRohanb


10. What are the rules for a local and global variable in Python?

A. In Python, variables that are only referenced inside a function are called implicitly global. If a variable is assigned a new value anywhere within the function’s body, it’s assumed to be a local. If a variable is ever assigned a new value inside the function, the variable is implicitly local, and we need to declare it as ‘global’ explicitly. To make a variable globally, we need to declare it by using global keyword. Local variables are accessible within local body only. Global variables are accessible anywhere in the program, and any function can access and modify its value.

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