Writing random numbers to csv-file

Question

I want to output a csv-file where the lines look like this: x,y,0,1 or x,y,1,0 where x and y are random integers from 1 to 5 with weighted probabilities. Unfortunately I get just this as a csv-file:

4,4,0,1
0,1
0,1
3,4,1,0
1,0
0,1
1,0
0,1
1,0
0,1

My python code looks like this:

import csv
import random
import numpy

l = [[[10,20,50,10,10],[20,20,20,20,20]],[[10,20,50,10,10],[20,20,20,20,20]]]

with open("test.csv", "wb") as f:
    writer = csv.writer(f)
    for i in range(10):
        x = random.randint(0,1)
        h = l[x]
        d =[]
        while len(h) > 0:
            a=numpy.array(h.pop(0))
            d.append(numpy.random.choice(range(1, 6), p=a/100.0))
        c = [0] * 2
        c[x]=1
        writer.writerow(d+c)

What do I do wrong?

Answer 1

You pop items from the lists in l . Once they are empty, while len(h) > 0: is never True and the while loop doesn't run. Try copying the sublists instead

import csv
import random
import numpy

l = [[[10,20,50,10,10],[20,20,20,20,20]],[[10,20,50,10,10],[20,20,20,20,20]]]

with open("test.csv", "wb") as f:
    writer = csv.writer(f)
    for i in range(10):
        x = random.randint(0,1)
        h = l[x][:]                # <-- copy list
        d =[]
        while len(h) > 0:
            a=numpy.array(h.pop(0))
            d.append(numpy.random.choice(range(1, 6), p=a/100.0))
        c = [0] * 2
        c[x]=1
        writer.writerow(d+c)

Or enumerate the sublist directly

import csv
import random
import numpy

l = [[[10,20,50,10,10],[20,20,20,20,20]],[[10,20,50,10,10],[20,20,20,20,20]]]

with open("test.csv", "wb") as f:
    writer = csv.writer(f)
    for i in range(10):
        x = random.randint(0,1)
        d =[]
        for h in l[x]:                # <-- enumerate list
            a=numpy.array(h)
            d.append(numpy.random.choice(range(1, 6), p=a/100.0))
        c = [0] * 2
        c[x]=1
        writer.writerow(d+c)