Adapted from :¶

100 numpy exercises¶

This is a collection of exercises that have been collected in the numpy mailing list, on stack overflow and in the numpy documentation. The goal of this collection is to offer a quick reference for both old and new users but also to provide a set of exercises for those who teach.

If you find an error or think you've a better way to solve some of them, feel free to open an issue at https://github.com/rougier/numpy-100

1. Import the numpy package under the name `np` (★☆☆)¶

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2. Print the numpy version and the configuration (★☆☆)¶

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3. Create a null vector of size 10 (★☆☆)¶

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6. Create a null vector of size 10 but the fifth value which is 1 (★☆☆)¶

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7. Create a vector with values ranging from 10 to 49 (★☆☆)¶

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8. Reverse a vector (first element becomes last) (★☆☆)¶

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9. Create a 3x3 matrix with values ranging from 0 to 8 (★☆☆)¶

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10. Find indices of non-zero elements from [1,2,0,0,4,0] (★☆☆)¶

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11. Create a 3x3 identity matrix (★☆☆)¶

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12. Create a 3x3x3 array with random values (★☆☆)¶

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13. Create a 10x10 array with random values and find the minimum and maximum values (★☆☆)¶

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14. Create a random vector of size 30 and find the mean value (★☆☆)¶

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15. Create a 2d array with 1 on the border and 0 inside (★☆☆)¶

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16. How to add a border (filled with 0's) around an existing array? (★☆☆)¶

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18. Create a 5x5 matrix with values 1,2,3,4 just below the diagonal (★☆☆)¶

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19. Create a 8x8 matrix and fill it with a checkerboard pattern (★☆☆)¶

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20. Consider a (6,7,8) shape array, what is the index (x,y,z) of the 100th element?¶

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22. Normalize a 5x5 random matrix (★☆☆)¶

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24. Multiply a 5x3 matrix by a 3x2 matrix (real matrix product) (★☆☆)¶

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25. Given a 1D array, negate all elements which are between 3 and 8, in place. (★☆☆)¶

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26. What is the output of the following script? (★☆☆)¶

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# Author: Jake VanderPlas

print(sum(range(5),-1))
from numpy import *
print(sum(range(5),-1))

27. Consider an integer vector Z, which of these expressions are legal? (★☆☆)¶

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Z**Z
2 << Z >> 2
Z <- Z
1j*Z
Z/1/1
Z<Z>Z

28. What are the result of the following expressions?¶

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print(np.array(0) / np.array(0))
print(np.array(0) // np.array(0))
print(np.array([np.nan]).astype(int).astype(float))

29. How to round away from zero a float array ? (★☆☆)¶

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30. How to find common values between two arrays? (★☆☆)¶

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36. Extract the integer part of a random array using 5 different methods (★★☆)¶

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37. Create a 5x5 matrix with row values ranging from 0 to 4 (★★☆)¶

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39. Create a vector of size 10 with values ranging from 0 to 1, both excluded (★★☆)¶

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40. Create a random vector of size 10 and sort it (★★☆)¶

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42. Consider two random array A and B, check if they are equal (★★☆)¶

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45. Create random vector of size 10 and replace the maximum value by 0 (★★☆)¶

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46. Create a structured array with `x` and `y` coordinates covering the [0,1]x[0,1] area (★★☆)¶

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48. Print the minimum and maximum representable value for each numpy scalar type (★★☆)¶

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50. How to find the closest value (to a given scalar) in a vector? (★★☆)¶

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58. Subtract the mean of each row of a matrix (★★☆)¶

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61. Find the nearest value from a given value in an array (★★☆)¶

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Adapted from :¶

100 numpy exercises¶

1. Import the numpy package under the name np (★☆☆)¶

2. Print the numpy version and the configuration (★☆☆)¶

3. Create a null vector of size 10 (★☆☆)¶

6. Create a null vector of size 10 but the fifth value which is 1 (★☆☆)¶

7. Create a vector with values ranging from 10 to 49 (★☆☆)¶

8. Reverse a vector (first element becomes last) (★☆☆)¶

9. Create a 3x3 matrix with values ranging from 0 to 8 (★☆☆)¶

10. Find indices of non-zero elements from [1,2,0,0,4,0] (★☆☆)¶

11. Create a 3x3 identity matrix (★☆☆)¶

12. Create a 3x3x3 array with random values (★☆☆)¶

13. Create a 10x10 array with random values and find the minimum and maximum values (★☆☆)¶

14. Create a random vector of size 30 and find the mean value (★☆☆)¶

15. Create a 2d array with 1 on the border and 0 inside (★☆☆)¶

16. How to add a border (filled with 0's) around an existing array? (★☆☆)¶

18. Create a 5x5 matrix with values 1,2,3,4 just below the diagonal (★☆☆)¶

19. Create a 8x8 matrix and fill it with a checkerboard pattern (★☆☆)¶

20. Consider a (6,7,8) shape array, what is the index (x,y,z) of the 100th element?¶

22. Normalize a 5x5 random matrix (★☆☆)¶

24. Multiply a 5x3 matrix by a 3x2 matrix (real matrix product) (★☆☆)¶

25. Given a 1D array, negate all elements which are between 3 and 8, in place. (★☆☆)¶

26. What is the output of the following script? (★☆☆)¶

27. Consider an integer vector Z, which of these expressions are legal? (★☆☆)¶

28. What are the result of the following expressions?¶

29. How to round away from zero a float array ? (★☆☆)¶

30. How to find common values between two arrays? (★☆☆)¶

36. Extract the integer part of a random array using 5 different methods (★★☆)¶

37. Create a 5x5 matrix with row values ranging from 0 to 4 (★★☆)¶

39. Create a vector of size 10 with values ranging from 0 to 1, both excluded (★★☆)¶

40. Create a random vector of size 10 and sort it (★★☆)¶

42. Consider two random array A and B, check if they are equal (★★☆)¶

45. Create random vector of size 10 and replace the maximum value by 0 (★★☆)¶

46. Create a structured array with x and y coordinates covering the [0,1]x[0,1] area (★★☆)¶

48. Print the minimum and maximum representable value for each numpy scalar type (★★☆)¶

50. How to find the closest value (to a given scalar) in a vector? (★★☆)¶

58. Subtract the mean of each row of a matrix (★★☆)¶

61. Find the nearest value from a given value in an array (★★☆)¶

1. Import the numpy package under the name `np` (★☆☆)¶

46. Create a structured array with `x` and `y` coordinates covering the [0,1]x[0,1] area (★★☆)¶