plt.scatter(P[:,0], P[:,1], s=S, lw = 1.5,
         edgecolors = C, facecolors='None')

# -*- coding:utf-8 -*-
import numpy as np
import matplotlib.pyplot as plt
fig = plt.figure(figsize=(9,6))
# 泡泡的数量
n = 50
size_min = 50
size_max = 50*50
# Ring position,rand可以产生2维数组
P = np.random.rand(n,2)
# Ring colors R,G,B,A
C = np.ones((n,4)) * (0,0,0,1)
# Alpha color channel goes from 0 (transparent) to 1 (opaque)
C[:,3] = np.linspace(0,1,n)
# Ring sizes
S = np.linspace(size_min, size_max, n)
# Scatter plot
plt.scatter(P[:,0], P[:,1], s=S, lw = 1.5,
         edgecolors = C, facecolors='None')
#range只能排列出整数，在排列小数时可以用到np.arange
plt.xlim(0,1), plt.xticks(np.arange(0,1.1,0.1))
plt.ylim(0,1), plt.yticks(np.arange(0,1.1,0.1))
plt.show()

from mpl_toolkits.mplot3d import Axes3D

projection='3d'

# -*- coding:utf-8 -*-
from mpl_toolkits.mplot3d import Axes3D
import numpy as np
import matplotlib.pyplot as plt
from pylab import *
mpl.rcParams['font.sans-serif'] = ['SimHei'] #防止中文乱码
fig = plt.figure(figsize=(9,6))
#添加参数projection
ax = fig.add_subplot(111,projection='3d')
z = np.linspace(0, 6, 1000)
r = 1
x = r * np.sin(np.pi*2*z)
y = r * np.cos(np.pi*2*z)
#c是颜色
ax.plot(x, y, z, label=u'螺旋线', c='r')
ax.legend()
#存成图片，支持png格式
# dpi每英寸长度的点数,画出的三维图是矢量图，可以设置保存的dpi
plt.savefig('3d_fig.png',dpi=200)
plt.show()