writing to a file from a function

gistfile1.py

# -*- coding: utf-8 -*-
import simuPOP as sim
import numpy as np
from simuPOP.utils import viewVars

pop = sim.Population(size = [550, 400], loci = 10, infoFields = ["age", "migrate_to"], subPopNames = ["croatia", "slovenia"])
sim.initInfo(pop = pop, values = np.random.choice([1, 2, 3, 4, 5], replace = True, size = 200), infoFields = "age")
sim.initGenotype(pop = pop, prop = [0.1]*10)
sim.initSex(pop, maleProp = 0.5)

pop.subPopSizes()
pop.subPopNames()
sim.splitSubPops(pop = pop, subPops = 0, sizes = [450, 100])
sim.splitSubPops(pop = pop, subPops = 2, sizes = [300, 100])
pop.subPopSizes()
pop.subPopNames()

sim.stat(pop = pop, popSize = "subPopSize_sp")
sim.stat(pop = pop, effectiveSize = sim.ALL_AVAIL, vars = "Ne_LD_sp")

    # Construct a dictionary that can be read in columns:
    #               pop_num, pop_name, x, 0.0, 0.01, 0.02, 0.05
    # population num __/      /       /   /     /     /     /
    # population name _______/       /   /     /     /     /
    # variable designation _________/   /     /     /     /
    # value without a cutoff __________/     /     /     /
    # value at cutoff of 0.01 ______________/     /     /
    # value at cutoff of 0.02 ___________________/     /
    # value at cutoff of 0.05 ________________________/
for p in range(pop.numSubPop()): # all subpops
    data = []
    xname = ["fit", "lci", "uci"]
    for x in range(3): # fit, lci, uci
        v = []
        for y in [0.0, 0.01, 0.02, 0.05]:
            v.append(pop.dvars().subPop[p]["Ne_LD"][y][x])
        data.append(v)
        # print("{pop}, {popname}, {x}, {data}".format(pop = p, popname = pop.subPopNames()[p], x = xname[x], data = data[x]))
        to_print = "{pop}, {popname}, {x}, {data0}, {data01}, {data02}, {data05}".format(pop = pop.subPopNames()[p], popname = p, x = xname[x],
                                                                                    data0 = data[x][0],
                                                                                    data01 = data[x][1],
                                                                                    data02 = data[x][2],
                                                                                    data05 = data[x][3])
        sim.pyOutput(to_print) # doesn't work
        print(to_print) # outputs fine, but only to console