Skip to content
Advertisement

Read in all csv files from a directory using Python

I hope this is not trivial but I am wondering the following:

If I have a specific folder with n csv files, how could I iteratively read all of them, one at a time, and perform some calculations on their values?

For a single file, for example, I do something like this and perform some calculations on the x array:

import csv
import os

directoryPath=raw_input('Directory path for native csv file: ') 
csvfile = numpy.genfromtxt(directoryPath, delimiter=",")
x=csvfile[:,2] #Creates the array that will undergo a set of calculations

I know that I can check how many csv files there are in a given folder (check here):

import glob
for files in glob.glob("*.csv"):
    print files 

But I failed to figure out how to possibly nest the numpy.genfromtxt() function in a for loop, so that I read in all the csv files of a directory that it is up to me to specify.

EDIT

The folder I have only has jpg and csv files. The latter are named eventX.csv, where X ranges from 1 to 50. The for loop I am referring to should therefore consider the file names the way they are.

Advertisement

Answer

That’s how I’d do it:

import os

directory = os.path.join("c:\","path")
for root,dirs,files in os.walk(directory):
    for file in files:
       if file.endswith(".csv"):
           f=open(file, 'r')
           #  perform calculation
           f.close()
User contributions licensed under: CC BY-SA
4 People found this is helpful
Advertisement