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NumPy: String Exercises, Practice, Solution

NumPy String [22 exercises with solution]

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NumPy: String

1. Write a NumPy program to concatenate element-wise two arrays of string. Go to the editor
Expected Output:
Array1:
['Python' 'PHP']
Array2:
[' Java' ' C++']
new array:
['Python Java' 'PHP C++']
Click me to see the sample solution

2. Write a NumPy program to repeat all the elements three times of a given array of string Go to the editor
Expected Output:
Original Array:
['Python' 'PHP' 'Java' 'C++']
New array:
['PythonPythonPython' 'PHPPHPPHP' 'JavaJavaJava' 'C++C++C++']
Click me to see the sample solution

3. Write a NumPy program to capitalize the first letter, lowercase, uppercase, swapcase, title-case of all the elements of a given array. Go to the editor
Expected Output:
Original Array:
['python' 'PHP' 'java' 'C++']
Capitalized: ['Python' 'Php' 'Java' 'C++']
Lowered: ['python' 'php' 'java' 'c++']
Uppered: ['PYTHON' 'PHP' 'JAVA' 'C++']
Swapcased: ['PYTHON' 'php' 'JAVA' 'c++']
Titlecased: ['Python' 'Php' 'Java' 'C++']
Click me to see the sample solution

4. Write a NumPy program to make the length of each element 15 of a given array and the string centered / left-justified / right-justified with paddings of _. Go to the editor
Original Array:
['python exercises' 'PHP' 'java' 'C++']
Centered = ['python exercise' '______PHP______' '______java_____' '______C++______'] Left = ['python exercise' 'PHP____________' 'java___________' 'C++____________'] Right = ['python exercise' '____________PHP' '___________java' '____________C++']
Click me to see the sample solution

5. Write a NumPy program to insert a space between characters of all the elements of a given array. Go to the editor
Note: First array elements raised to powers from second array
Expected Output:
Original Array:
['python exercises' 'PHP' 'java' 'C++']
['p y t h o n e x e r c i s e s' 'P H P' 'j a v a' 'C + +']
Click me to see the sample solution

6. Write a NumPy program to encode all the elements of a given array in cp500 and decode it again. Go to the editor
Sample Output:
encoded = [b'\x97\xa8\xa3\x88\x96\[email protected]\x85\xa7\x85\x99\x83\x89\xa2\x85\xa2'
b'\xd7\xc8\xd7' b'\x91\x81\xa5\x81' b'\xc3NN']
decoded = ['python exercises' 'PHP' 'java' 'C++']
Click me to see the sample solution

7. Write a NumPy program to remove the leading and trailing whitespaces of all the elements of a given array. Go to the editor
Sample output:
Original array:
[ -10.2 122.2 0.2]
Element-wise absolute value:
[ 10.2 122.2 0.2]
Click me to see the sample solution

8. Write a NumPy program to remove the leading whitespaces of all the elements of a given array. Go to the editor
Sample Output:
Original Array:
[' python exercises ' ' PHP ' ' java ' ' C++']
Remove the leading whitespaces : ['python exercises ' 'PHP ' 'java ' 'C++']
Click me to see the sample solution

9. Write a NumPy program to remove the trailing whitespaces of all the elements of a given array. Go to the editor
Sample Output:
Original Array:
[' python exercises ' ' PHP ' ' java ' ' C++']
Remove the trailing whitespaces : [' python exercises' ' PHP' ' java' ' C++']
Click me to see the sample solution

10. Write a NumPy program to split the element of a given array with spaces. Go to the editor
Sample Output:
Original Array:
['Python PHP Java C++']
Split the element of the said array with spaces:
[list(['Python', 'PHP', 'Java', 'C++'])]
Click me to see the sample solution

11. Write a NumPy program to split the element of a given array to multiple lines. Go to the editor
Sample output:
Original Array:
['Python\\Exercises, Practice, Solution']
[list(['Python\\Exercises, Practice, Solution'])]
Click me to see the sample solution

12. Write a NumPy program to make all the elements of a given string to a numeric string of 5 digits with zeros on its left. Go to the editor
Sample output:
Original Array:
['2' '11' '234' '1234' '12345']
Numeric string of 5 digits with zeros:
['00002' '00011' '00234' '01234' '12345']
Click me to see the sample solution

13. Write a NumPy program to replace "PHP" with "Python" in the element of a given array. Go to the editor
Sample Output:
Original Array:
['PHP Exercises, Practice, Solution']
New array:
['Python Exercises, Practice, Solution']
Click me to see the sample solution

14. Write a NumPy program to test equal, not equal, greater equal, greater and less test of all the elements of two given arrays. Go to the editor
Expected Output:
Array1:
['Hello' 'PHP' 'JS' 'examples' 'html']
Array2:
['Hello' 'php' 'Java' 'examples' 'html']
Equal test:
[ True False False True True]
Not equal test:
[False True True False False]
Less equal test:
[ True True True True True]
Greater equal test:
[ True False False True True]
Less test:
[False True True False False]
Click me to see the sample solution

15. Write a NumPy program to count the number of "P" in a given array, element-wise. Go to the editor
Sample Output:
Original Array:
['Python' 'PHP' 'JS' 'examples' 'html']
Number of 'P':
[1 2 0 0 0]
Click me to see the sample solution

16. Write a NumPy program to count the lowest index of "P" in a given array, element-wise. Go to the editor
Original Array:
['Python' 'PHP' 'JS' 'EXAMPLES' 'HTML']
count the lowest index of 'P':
[ 0 0 -1 4 -1]
Click me to see the sample solution

17. Write a NumPy program to check whether each element of a given array is composed of digits only, lower case letters only and upper case letters only. Go to the editor
Sample output:
Original Array:
['Python' 'PHP' 'JS' 'Examples' 'html5' '5']
Digits only = [False False False False False True]
Lower cases only = [False False False False True False]
Upper cases only = [False True True False False False]
Click me to see the sample solution

18. Write a NumPy program to check whether each element of a given array starts with "P". Go to the editor
Sample output:
Original Array:
['Python' 'PHP' 'JS' 'examples' 'html']
Test if each element of the said array starts with 'P':
[ True True False False False]
Click me to see the sample solution

19. Write a NumPy program to add two zeros to the beginning of each element of a given array of string values. Go to the editor
Sample output:
Original array:
['1.12' '2.23' '3.71' '4.23' '5.11']
Add two zeros to the beginning of each element of the said array:
['001.12' '002.23' '003.71' '004.23' '005.11']
Alternate method:
['001.12' '002.23' '003.71' '004.23' '005.11']
Click me to see the sample solution

20. Write a NumPy program to replace a specific character with another in a given array of string values. Go to the editor
Sample output:
Original array of string values:
[['Python-NumPy-Exercises']
['-Python-']]
Replace '-' with '=' character in the said array of string values:
[['Python==NumPy==Exercises']
['==Python==']]
Replace '-' with ' ' character in the said array of string values:
[['Python NumPy Exercises']
['Python']]
Click me to see the sample solution

21. Write a NumPy program to count a given word in each row of a given array of string values. Go to the editor
Sample output:
Original array of string values:
[['Python' 'NumPy' 'Exercises']
['Python' 'Pandas' 'Exercises']
['Python' 'Machine learning' 'Python']]
Count 'Python' row wise in the above array of string values:
[[1 0 0]
[1 0 0]
[1 0 1]]
Click me to see the sample solution

22. Write a NumPy program to split a given text into lines and split the single line into array values. Go to the editor
Sample output:
Original text:
01 V Debby Pramod
02 V Artemiy Ellie
03 V Baptist Kamal
04 V Lavanya Davide
05 V Fulton Antwan
06 V Euanthe Sandeep
07 V Endzela Sanda
08 V Victoire Waman
09 V Briar Nur
10 V Rose Lykos
Array from the said text:
[['01' 'V' 'Debby Pramod']
['02' 'V' 'Artemiy Ellie']
['03' 'V' 'Baptist Kamal']
['04' 'V' 'Lavanya Davide']
['05' 'V' 'Fulton Antwan']
['06' 'V' 'Euanthe Sandeep']
['07' 'V' 'Endzela Sanda']
['08' 'V' 'Victoire Waman']
['09' 'V' 'Briar Nur']
['10' 'V' 'Rose Lykos']]
Click me to see the sample solution

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Python: Tips of the Day

Finding the most common elements in an iterable:

Example:

# collections.Counter lets you find the most common
# elements in an iterable:

import collections
c = collections.Counter('helloworld')

print(c)

print (c.most_common(3))

Output:

Counter({'l': 3, 'o': 2, 'h': 1, 'e': 1, 'w': 1, 'r': 1, 'd': 1})
[('l', 3), ('o', 2), ('h', 1)]