Amazing hacks of Python

PythonServer Side ProgrammingProgramming

Python is an amazing programming language that can do many interesting things due to its huge set of libraries. Here are some common hacks and things that will be helpful to you while programming.

SSPrinting the same character multiple times in python.

Printing repeated character by typing the same character set as many times as we want or looping through if the values are large is commonly used in other programming languages. But python has something else in its trunk to ease this printing of recursive characters.

The below code is used to print recursive characters in python,

Example

print("I love program at tutorials point "+"TP"*4);

Output

I love program at tutorials point TPTPTPTP

Printing elements of a list in different ways

List is just like a nonhomogeneous array. And for printing the elements of a list in python there are multiple methods defined. By default, in printing the list in python adds up the square bracket and single quotes. But in python, you have the option to print the list in a more effective manner. This work is done in python using the join() method.

The join methods convert the list into a string. Each element of the list is connected with the string that called the join. Let’s see how this works.

Example

bikes = ['thunderbird' , 'Pulsar' , 'R15' , 'Duke']
# traditional method of printing the list
print("Bikes are :", bikes)
# printing list using join method
print("Bikes are : %s" %','.join(bikes))
print('Bikes are : ',(" and ".join(bikes)))

Output

Bikes are : ['thunderbird', 'Pulsar', 'R15', 'Duke']
Bikes are : thunderbird,Pulsar,R15,Duke
Bikes are : thunderbird and Pulsar and R15 and Duke

Printing multiple lists simultaneously

Python provides a method to print elements of more than one list simultaneously in pair form. There's a method called zip that merges two equal length lists into pairs.

Example

bikes = ['thunderbird' , 'Pulsar' , 'R15' , 'Duke']
speed = ['142' , '135' , '137' , '145']
for bike, maxspeed in zip(bikes , speed):
print(bike, maxspeed)

Output

thunderbird 142
Pulsar 135
R15 137
Duke 145

ShortHand trick to swapping values

Python programming language supports an inbuilt shorthand trick to swap two values. This trick provides an easy way to swap values without using any extra variable. Let's see a program that shows how this works −

Example

value1 = 325
value2 = 976
print("value1 = ",value1)
print("value2 = ",value2)
value1,value2 = value2,value1
print("\nSwapped values")
print("value1 = ",value1)
print("values = ",value2)

Output

value1 = 325
value2 = 976
Swapped values
value1 = 976
values = 325

Reversing a string in python

Python provides a shorthand trick to reverse a string. Let’s see an example of how to reverse a string in python −

Example

value1 = 'Hello! Welcome to tutorials point'
print(value1[::-1])
number = 934827165303
print(int(str(number)[::-1]))

Output

tniop slairotut ot emocleW !olleH
303561728439

Returning multiple values by a function in python

In python, the function can return multiple values in python i.e. you can return multiple values instead of single.

Example

def multiple() :
return 1*3 , 2*3 , 3*3 , 4*3 , 5*3
val1, val2, val3, val4, val5 = multiple()
print(val1, val2, val3, val4, val5)

Output

3 6 9 12 15

Printing index along with values in a for-in loop

In python, looping over values using a for-in loop yields values only. But if we want to access the index too we need to use an enumerate which will return index with the value.

Let’s see an example of how it works −

Example

bikes = ['thunderbird' , 'Pulsar' , 'R15' , 'Duke']
for i, bike in enumerate(bikes) :
print(i, bike)

Output

0 thunderbird
1 Pulsar
2 R15
3 Duke

Slice operation in python

The slice operation in python is for getting items from a list. Let’s look at an example of how to slice operation works −

Example

bikes = ['thunderbird' , 'Pulsar' , 'R15' , 'Duke', 'S1000RR']
print(bikes[0:3]) #print first 3 elements
print(bikes[::2]) #print alternate elements
print(bikes[::-1]) #prints reversed list
print(bikes[::-2]) #prints reversed list with alternate elements

Output

['thunderbird', 'Pulsar', 'R15']
['thunderbird', 'R15', 'S1000RR']
['S1000RR', 'Duke', 'R15', 'Pulsar', 'thunderbird']
['S1000RR', 'R15', 'thunderbird']

Convert a string to list in python

Sometimes there is an urge to convert the inputted string into other types. So, here is a method in python that is used to convert string to list in python. Let's see how its done −

Example

name = "3 34 67 12 78"
converted_list = list(map(int, name.split()))
print(converted_list)

Output

[3, 34, 67, 12, 78]

Converting a list of the list into a single list

In python, the multidimensional list can be converted to a one-dimensional list. The method chain.from_iterable() is used for this task. As it returns elements from the list of the list until the last element is encountered. Let’s see an example of how it works −

Example

import itertools
dob = [ [3 , 30], [6 , 12] , [8 , 17] ]
print(dob)
dates = list(itertools.chain.from_iterable(dob))
print(dates)

Output

[[3, 30], [6, 12], [8, 17]]
[3, 30, 6, 12, 8, 17]
raja
Published on 24-Oct-2019 11:19:28
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