email_parsing_size_addresses_domains_only.py

# http://stackoverflow.com/questions/17872094/python-how-to-parse-things-such-as-from-to-body-from-a-raw-email-source-w
# http://stackoverflow.com/a/14773896/3784441
# http://stackoverflow.com/a/5749208/3784441

# unsure whether to use email.parser or email.message
import os, email.message
from email.parser import Parser
from pprint import pprint

# change to working directory
os.chdir("..\\email_parsing-emails\\all_emails")
#os.chdir("..\\email_parsing-emails\\10_emails")
print "Working directory: " + os.getcwd()

# count how many files are in the working directory and print that
number_of_files = len([name for name in os.listdir('.') if os.path.isfile(name)])
files_completed = 0
print str(number_of_files) + " files to parse."

def get_email_address_only(from_string):
	""" removes all text except the email address from the From string """
	# Split the From email so you are left with only the email address, no extra characters. Delineated by < and >
	from_string_split = from_string.split("<")
	return_value = from_string_split[-1].split(">")[0]
	return return_value
	
def get_email_address_domain_only(email_address_string):
	""" returns the domain portion of an email address """
	# Split the email address so we get the From email domain
	return_value = email_address_string.split("@")[-1]
	return return_value

# open the output file. This keeps it open until everything else is done, then closes it properly.
with open ("output_size_addresses_domains_only.csv", "w") as output_file:
	
	# write the column headers
	output_file.write("from address,from domain,file size\n")
	
	# iterate over every file in the directory
	for current_email_file in os.listdir(os.getcwd()):
	
	# if the file ends in .eml, use it.
		if current_email_file.endswith(".eml"):

		# get the file size. We'll store this along with the From email address.
			current_file_size = os.stat(current_email_file).st_size

			# open the file
			with open (current_email_file, "r") as current_email_file_opened:

				# dump the entire file into a String variable.
				# This could probably be improved by grabbing parts of the email from the file instead of reading the whole thing in.
				current_email_text = current_email_file_opened.read()
				
				# create an email.message object using the string we just read in.
				current_email_message = email.message_from_string(current_email_text)
				
				# Grab the From field in the email
				from_string = current_email_message['From']
				if (from_string == None):
					from_string = ""
					
				from_string_email_address_only = get_email_address_only(from_string)
				#print from_string_email_address_only
				from_string_domain = get_email_address_domain_only( from_string_email_address_only )
				#print from_string_domain
				
				"""# Split the From email so you are left with only the email address, no extra characters. Delineated by < and >
				from_string_split = from_string.split("<")
				from_string_email_address_only = from_string_split[-1].split(">")
				
				# Split the email address so we get the From email domain
				from_string_domain = from_string_email_address_only[0].split("@")"""
				
				# testing: print the email Subject from the email.message object.
				# print from_string_split[0]
				# output the From email address, From domain, and file size to the CSV file
				output_file.write(from_string_email_address_only + "," + from_string_domain + "," + str(current_file_size) + "\n")
				
				# iterate the # of files completed
				files_completed += 1
				
				# every 100 files, print progress
				if (files_completed % 1000 == 0):
					print str(files_completed) + " of " + str(number_of_files) + " files completed. " + str( 100 * round( (files_completed / float(number_of_files) ), 4 )) + "% complete."
				
				# pprint (vars(current_email_message))


print "Finished."