import random
def my_func(a, b, n, file):
spis = [random.uniform(a,b) for _ in range(n)]
fp = open(file=file, mode='w')
for i in range(round(len(spis)/3)+1):
fp.write(str(spis[i*3:(i+1)*3])+'\n')
fp.close()
return spis