一、计算e(x)：

import math
result = math.exp(x)import numpy as np
result = np.exp(x)

二、matplotlib.pyplot坐标无法显示中文：

plt.rcParams['font.family'] = ['sans-serif']
plt.rcParams['font.sans-serif'] = ['SimHei']

三、matplotlib.pyplot横纵坐标无法按顺序显示：

int(money)   #将数据改为实数类型

四、shape函数的性质：

>>> x = np.array([[1, 2, 3], [4, 5, 6]])     # 只适用于numpy数组
>>> x.shape  
(2, 3)                                           # 输出一个元组
>>> x.shape[0] 
2
>>> x.shape[1] 
3

五、np.shape()的使用：

np.shape(x)或x.shape，返回元组。

六、np.max()和np.maximum()的使用：

np.max()求自身的最大值，而np.maxmum()求两者之间的最大值。

>>>A = np.array([[1,8,3,6,5],[9,2,7,4,5]])
>>>np.max(A)
9
>>>np.max(A, axis=0)
array([9, 8, 7, 6, 5])
>>>np.max(A, axis=1)
array([8, 9])

>>>np.maximum(A, 5)
array([[5, 8, 5, 6, 5],[9, 5, 7, 5, 5]])
>>>np.maximum(A,10)
array([[10, 10, 10, 10, 10],[10, 10, 10, 10, 10]])

七、np.hstack&np.vstack

np.hstack：接受一个输入，水平方向拼接
np.vstack：接受一个输入，竖直方向拼接，注意拼接元素的维度

>>> import numpy as np
>>> y = np.hstack(1, (2,3,4), 4)
Traceback (most recent call last):File "<stdin>", line 1, in <module>File "<__array_function__ internals>", line 198, in hstack
TypeError: hstack() takes 1 positional argument but 3 were given
>>> y = np.hstack((1, (2,3,4), 4)) 
>>> y
array([1, 2, 3, 4, 4])
>>> y.shape
(5,)

>>> y = np.vstack((1, (2,3,4), 4))
Traceback (most recent call last):File "<stdin>", line 1, in <module>File "<__array_function__ internals>", line 200, in vstackFile "D:\Program Files\anaconda\Lib\site-packages\numpy\core\shape_base.py", line 296, in vstackreturn _nx.concatenate(arrs, 0, dtype=dtype, casting=casting)^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^File "<__array_function__ internals>", line 200, in concatenate
ValueError: all the input array dimensions except for the concatenation axis must match exactly, but along dimension 1, the array at index 0 ha
s size 1 and the array at index 1 has size 3
>>> y = np.vstack((1, 5, 4))       
>>> y
array([[1],[5],[4]])
>>> y.shape
(3, 1)

八、np.random.normal()

生成指定方差、均值、维度的分布