How to print random n rows from a csv file?-CodePudding

So i have a big csv file and my code prints all the rows but i want to print, for example, only 20 random rows from 100000 rows. I know that somehow with random.sample u can do that, but i don't really know how. Any suggestions?

There is my code:

import csv

with open(r'Z:/datasets/room-segmentation/labeling/test_examples_doors/labels.csv') as csvfile:   
 data = csv.DictReader(csvfile)
 for row in data:
     if row['open']=='1':
print(row['image'], row['open'])

CodePudding user response：

I assume you want to randomly sample your data, rather than just take the first 20 rows?

In this case you can convert data to a list and then sample it:

import csv
import random
with open(r'Z:/datasets/room-segmentation/labeling/test_examples_doors/labels.csv') as csvfile:
    data = csv.DictReader(csvfile)
sampled_data = random.sample(list(data), 20)

CodePudding user response：

If you don't need to code this yourself, GoCSV has the sample command which does just this:

gocsv sample -n 20 labels.csv

CodePudding user response：

I don't quite understand your question but to just get 20 rows you can just replace the code with a counter

x = 0
for row in data:
    x  = 1
    print(row['image'], row['open'])
    if x == 20:
        break

EDIT: Okay I get it, just get a random sample from the list and then delete that sample, then get another sample.

for x in range(20):
    num = random.randint(0,len(data))
    print(data[num]['image'], data[num]['open'])
    del data[num]