Example code and input data for Stack Overflow question

plot_3d_surface_xyz.py

# -*- coding: utf-8 -*-
from mpl_toolkits.mplot3d import Axes3D
from matplotlib.mlab import griddata
from matplotlib import cm
from matplotlib.ticker import LinearLocator, FormatStrFormatter
import matplotlib.pyplot as plt
import numpy as np
import sys

def xyz_ret(file):
    f = open(file, 'r')

    xyz = []
    print "test"
    for i in f:
        ret = i.replace('\n','')
        split_ret = ret.split(',')
        xyz.append(map(float,(split_ret)))

    xyz =  np.array(xyz)  
    print xyz    
    return xyz[:,0],xyz[:,1],xyz[:,2]     

x,y,z = xyz_ret('xyz.csv')

fig = plt.figure()
ax = fig.add_subplot(111, projection='3d')

xi = np.linspace(min(x), max(x))
yi = np.linspace(min(y), max(y))

X, Y = np.meshgrid(xi, yi)
Z = griddata(x, y, z, xi, yi)
surf = ax.plot_surface(X, Y, Z, rstride=1, cstride=1, cmap=cm.coolwarm,
        linewidth=0)
plt.colorbar(surf, shrink=0.5, aspect=10)
ax.set_zlim3d(min(z), max(z))
plt.show()

xyz.csv