Python：读取csv文件并将列保存为变量

Question

I'm wanting to read in a csv and save the first two columns as variables. This is what I have so far:

import sys, os, subprocess, shutil, time, string #these are for other things in the program :)
import csv

csvfile = list(csv.reader(open('test.csv')))   #read in the csv file

csv_dic = []

for row in csvfile:
        csv_dic.append(row);

for row in csv_dic:
       for column in row:
             print column, "***",   #I can print out the column
       print

I can print out columns, but would like to have it so I can have different variables for column 'arrays'.

For example, I am wanting to store the first column as 'frames' and the second as 'peaks', so to have it so, for example, frames[2] holds the second value in the first column and I can reference it.

Thank you.

Answer 1

Here's one way to do it:

frames = []
peaks = []

for row in csv_dic:
    frames.append(row[0])
    peaks.append(row[1])
    for column in row:
        print column, "***",   #I can print out the column
    print

Note that I am making one big assumption: that the two columns you want are exactly the first two columns of the CSV file. But this should do what you want. row[0] is the value in the first column of the row, and likewise, row[1] is the second column.

Now, if you want to do an unknown number of columns, you'll have to use another method (like a dictionary, perhaps).

Answer 2

Simple to do with the CSV module which you are already using. Here is a dictionary method and an array method.

dictionary

import csv
var1 = "frames"
var2 = "peaks"
csv_dic={var1:[], var2:[]}
csvFile = csv.reader(open('test.csv', 'rb'))
for row in csvFile:
  csv_dic[var1].append(row[0])
  csv_dic[var2].append(row[1])

again assuming that you only are worried about first two elements of each row.

Here is a method that will get you everything into your array, here called data . This is relatively fast for large files.

array

import csv
with open('test.csv','rb') as file:
    rows = csv.reader(file, 
                      delimiter = ',', 
                      quotechar = '"')
    data = [data for data in rows]