（一）基础学习
学习渠道：阿里天池AI学习——Numpy基础（传送门）
（二）练习篇
练习渠道：Numpy基础100题（Part 1）
1. Import the numpy package under the name np(★☆☆)
1 import numpy as np
2. Print the numpy version and the configuration(★☆☆)
1 print(np.version) 2 np.show_config()
3. Create a null vector of size 10(★☆☆)
1 arr = np.zeros(10) 2 print(arr)
运行结果：[0. 0. 0. 0. 0. 0. 0. 0. 0. 0.]
4. How to find the memory size of any array (★☆☆)
1 print("%d bytes" %(arr.size*arr.itemsize))
运行结果：80 bytes
5. How to get the documentation of the numpy add function from the command line? (★☆☆)
np.add?
6. Create a null vector of size 10 but the fifth value which is 1 (★☆☆)
1 arr = np.zeros(10) 2 arr[4] = 1; 3 print(arr)
运行结果：[0. 0. 0. 0. 1. 0. 0. 0. 0. 0.]
7. Create a vector with values ranging from 10 to 49 (★☆☆)
1 arr = np.arange(10,50) 2 print(arr)
运行结果：[10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49]
8. Reverse a vector (first element becomes last) (★☆☆)
1 arr = np.arange(10,50) 2 print(arr[::-1])
运行结果：[49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10]
9. Create a 3x3 matrix with values ranging from 0 to 8 (★☆☆)
1 arr = np.arange(9).reshape(3,3) 2 print(arr)
运行结果：[[0 1 2] [3 4 5] [6 7 8]]
10. Find indices of non-zero elements from [1,2,0,0,4,0] (★☆☆)
1 arr = np.array([1,2,0,0,4,0]) 2 print(arr.nonzero()[0])
运行结果：[0 1 4]