读入文件

python本身方法：

f=open("xx.csv","r")
b=f.read()
rows=b.split('\n')
full_data = []
for row in rows:
    cols_in_a_row=row.split(',')
    full_data.append(cols_in_a_row)

csv方法：

import csv
f = open("la_weather.csv", 'r')
csvreader = csv.reader(f)
data = list(csvreader)

NumPy方法：

import numpy
# Note that we don't need to use the open function to open it -- numpy will take care of that.
# numpy.ndarray
nfl = numpy.genfromtxt("nfl.csv", delimiter=",",dtype="U75", skip_header=1)

Pandas方法：

import pandas
# DATAFRAME
housing_2013 = pandas.read_csv("Hud_2013.csv")