import re
dataset_names = ["moscow", "new-york"]
text = """2008 11 186
2009 11 281
2011 11 776
2012 11 856
2011 11 776
2012 11 856"""
prepare_text = re.split('\t+|\n+', text)
out = {k: [{'value_{}'.format(i+1): prepare_text[t+i] for i in range(2)} for t in range(0,len(prepare_text), 2)] for k in dataset_names}
print(out)