HackerRank Python Solution - Strings - Text Alignment

• In Python, a string of text can be aligned left, right and center.

.ljust(width):

• This method returns a left-aligned string of length width.

>>> width = 20
>>> print 'HackerRank'.ljust(width,'-')
HackerRank----------

HackerRank Python Solution - Strings - String Validators

• Python has built-in string validation methods for basic data. It can check if a string is composed of alphabetical characters, alphanumeric characters, digits, etc.

str.isalnum():

• This method checks if all the characters of a string are alphanumeric (a-z, A-Z and 0-9).

>>> print 'ab123'.isalnum()
True
>>> print 'ab123#'.isalnum()
False

HackerRank Python Solution - Strings - Find a String

• In this challenge, the user enters a string and a substring. You have to print the number of times that the substring occurs in the given string. String traversal will take place from left to right, not from right to left.
• NOTE: String letters are case-sensitive.

Input Format:

• The first line of input contains the original string. The next line contains the substring.

HackerRank Python Solution - Strings - Mutations

• We have seen that lists are mutable (they can be changed), and tuples are immutable (they cannot be changed).
• Let's try to understand this with an example.
• You are given an immutable string, and you want to make changes to it.

Example:

>>> string = "abracadabra"

HackerRank Python Solution - Strings - What's Your Name?

You are given the firstname and lastname of a person on two different lines. Your task is to read them and print the following:

 

Hello firstname lastname! You just delved into python.

Function Description:

• Complete the print_full_name function in the editor below.
• print_full_name has the following parameters:
• string first: the first name
• string last: the last name
• Prints string: 'Hello firstname lastname! You just delved into python' where and are replaced with first and last.

HackerRank Python Solution - Strings - Split and Join

In Python, a string can be split on a delimiter.

Example:

>>> a = "this is a string"
>>> a = a.split(" ") # a is converted to a list of strings. 
>>> print a
['this', 'is', 'a', 'string']

Joining a string is simple:

 

>>> a = "-".join(a)
>>> print a
this-is-a-string 

HackerRank Python Solution - Strings - sWAP cASE

You are given a string and your task is to swap cases. In other words, convert all lowercase letters to uppercase letters and vice versa.

For Example:

Www.HackerRank.com → wWW.hACKERrANK.COM
Pythonist 2 → pYTHONIST 2  

HackerRank Python Solution - Strings - Designer Door Mat

Mr. Vincent works in a doormat manufacturing company. One day, he designed a new doormat with the following specifications:

• Mat size must be N x M. (N is an odd natural number, and M is 3 times N.)
• The design should have 'WELCOME' written in the center.
• The design pattern should only use |,. and - characters.

HackerRank Python Solution - Built-Ins - ginortS

• You are given a string S. S contains alphanumeric characters only.

• Your task is to sort the string S in the following manner:
• All sorted lowercase letters are ahead of uppercase letters.
• All sorted uppercase letters are ahead of digits.
• All sorted odd digits are ahead of sorted even digits.

HackerRank Python Solution - Built-Ins - Any or All

any():

• This expression returns True if any element of the iterable is true. If the iterable is empty, it will return False.

Code:

>>> any([1>0,1==0,1<0])
True
>>> any([1<0,2<1,3<2])
False

HackerRank Python Solution - Built-Ins - Athlete Sort

• You are given a spreadsheet that contains a list of N athletes and their details (such as age, height, weight, and so on). You are required to sort the data based on the K^th attribute and print the final resulting table. Follow the example given below for a better understanding.

• Note that K is indexed from 0 to M-1, where M is the number of attributes.
• Note: If two attributes are the same for different rows, for example, if two athletes are of the same age, print the row that appeared first in the input.