Save results to csv file with Python

Question

import csv  with open('test.csv', 'rb') as f:   data = list(csv.reader(f))  import collections counter = collections.defaultdict(int) for row in data:     counter[row[1]] += 1 for row in data:     if counter[row[1]] >= 4:       writer = csv.writer(open("test1.csv", "wb"))       writer.writerows(row) 

I am getting strange output! What is wrong with this code?

Answer 1

I know the question is asking about your "csv" package implementation, but for your information, there are options that are much simpler — numpy, for instance.

import numpy as np np.savetxt('data.csv', (col1_array, col2_array, col3_array), delimiter=',') 

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(This answer posted 6 years later, for posterity's sake.)

In a different case similar to what you're asking about, say you have two columns like this:

names = ['Player Name', 'Foo', 'Bar'] scores = ['Score', 250, 500] 

You could save it like this:

np.savetxt('scores.csv', [p for p in zip(names, scores)], delimiter=',', fmt='%s') 

scores.csv would look like this:

Player Name,Score Foo,250 Bar,500