Efficient Python 1: Play with Numpy, loops, Lists, Arrays

Solve these quizzes and learn how to make your python codes concise and efficient

1. Sum of arrays

Simple Code

Computing_Sum_of_an_Array1

Computing sum of an array with for loop

num

numbers

total


       = [1, 2, 3, 4, 5]
total = 0
for num in numbers:
    total +=       
print(      )

Output:

Advanced Code

Computing_Sum_of_an_Array2

Computing sum of an array with sum()

[1, 2, 3, 4, 5]

sum

total


numbers =       
      
 =       (numbers)
print(total)

Output:

2. Mean of arrays

Simple Code

Computing_Mean_of_an_Array1

Computing mean of an array with for loop

len(numbers)

mean


numbers = [1, 2, 3, 4, 5]
total = 0
for num in numbers:
    total        num
mean = total /       
print(      )

Output:

Advanced Code

Computing_Mean_of_an_Array2

Computing mean of an array with mean function

numpy

numbers

np.mean


import        as np
       = [1, 2, 3, 4, 5]
mean =       (numbers)
      (mean)

Output:

3. Create Identity Matrix

Simple Code

Creating_Identity_Matrix_1

Create identity matrix with for loops

row

range

i == j

append(1)

append(0)


n = 4
identity_matrix = []
for       
 in       (n):
         = []
  for        in range(n):
    if       :
      row.      
    else:
      row.      
  identity_matrix.append(row)
  print(row)

Output:

[1, 0, 0, 0]
[0, 1, 0, 0]
[0, 0, 1, 0]
[0, 0, 0, 1]

Advanced Code

Creating_Identity_Matrix_2

Create identity matrix with numpy library

np.eye

identity_matrix


import numpy as np
n = 4
      
 =       (n)
print(identity_matrix)

Output:

[[1. 0. 0. 0.]
 [0. 1. 0. 0.]
 [0. 0. 1. 0.]
 [0. 0. 0. 1.]]

4. Remove Duplicates

Simple Code

Remove_duplicates_from_list_1

Remove duplicates from list using for loop

numbers

[1, 2, 2, 3, 4, 4, 5]

num


numbers =       
unique_numbers = []
for num in       :
    if        not in unique_numbers:
        unique_numbers.append(num)

Output:

[1, 2, 3, 4, 5]

Advanced Code

Remove_duplicates_from_list_2

Remove duplicates from list using set

set

numbers

list

[1, 2, 2, 3, 4, 4, 5]


numbers =       
unique_numbers =       
(      
(      ))

Output:

[1, 2, 3, 4, 5]

5. Filter Even Numbers

Simple Code

Filtering_Even_Numbers_1

Filtering_Even_Numbers from a List

numbers

% 2

append


       = [1, 2, 3, 4, 5]
even_numbers = []
for num in numbers:
      if num        == 0:
          even_numbers.      (num)

Output:

[2, 4]

Advanced Code

Filtering_Even_Numbers_2

Filtering_Even_Numbers from a List

num

[1, 2, 3, 4, 5]

% 2


numbers =       
even_numbers = [num for       
 in numbers if num        == 0]

Output:

[2, 4]

Efficient python 2

This is the second segment of Efficient python : From Long and Basic to Short

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