# Read in JSON *.txt file to a list of Python dictionaries named "records" 
# (using the JSON module and loads() function):

	import json
	path = 'path/to/text/file.txt'
	records = [json.loads(line) for line in open(path)]


# Create a list of "tz" items from the dictionaries in "records"
# (not all of the dictionaries have the field "tz" so use "if...in"
time_zones = [rec['tz'] for rec in records if 'tz' in rec]