Translates a bulky file with pre and post processing. Takes care of rate limit of Google Translate API.

translate.py

#!/usr/bin/python
# -*- coding: utf-8 -*-

from googletrans import Translator
import time

BATCH_SIZE = 300
WAIT = 105

INPUT_FILE = 'strings.xml'
PRE_PROCESSED_FILE = 'pre_strings.xml'
OUTPUT_FILE = 'en_strings.xml'

batches = []
translator = Translator()

'''
Create output file
'''
open(OUTPUT_FILE, 'a').close()
'''
Empty output file
'''
open(OUTPUT_FILE, 'w').close()

'''
Pre processing
'''
with open(INPUT_FILE, 'r') as file:
  text = file.read()

text = text.replace("<strong>", "").replace("</strong>", "")
text = text.replace("<b>", "").replace("</b>", "")

with open(PRE_PROCESSED_FILE, 'w') as file:
  file.write(text)

print("Pre processing done!")

'''
Read all lines from the file to be translated
'''
with open(PRE_PROCESSED_FILE, 'r') as file:
  text = file.readlines()

'''
Create batches to handle API limit
RATE LIMIT: 1,000,000 characters per 100 sec
https://cloud.google.com/translate/quotas
'''
batches = [text[i:i + BATCH_SIZE] for i in xrange(0, len(text), BATCH_SIZE)]

'''
Translate each batch
'''
batch_ctr = 0
for batch in batches:
	strings_to_translate = []
	translated_strings = []
	en_text = []

	batch_ctr += 1
	for line in batch:
		if "<string name=" in line and "</string>" in line:
			curr_line = line[line.index(">")+1:]
			curr_line = curr_line[:curr_line.index("</string>")]
			strings_to_translate.append(curr_line)

	translations = translator.translate(strings_to_translate, dest='en')

	for translation in translations:
		translated_strings.append(translation.text)

	counter = 0
	for line in batch:
		en_line = line
		if "<string name=" in line and "</string>" in line:
			left = line[:line.index(">") + 1]
			right = line[line.index("</string>"):]
			if isinstance(translated_strings[counter], unicode):
				translated_strings[counter] = translated_strings[counter].encode('utf-8')
			en_line = left + translated_strings[counter] + right
			counter += 1
		en_text.append(en_line)

	print("\nBATCH {} DONE".format(batch_ctr))

	with open(OUTPUT_FILE, 'a') as file:
		for i in range(len(en_text)):
			if isinstance(en_text[i], unicode):
				en_text[i] = en_text[i].encode('utf-8')
			try:
				file.write(en_text[i])
			except UnicodeDecodeError as e:
				print(type(en_text[i]))
				print(("Exception: " + en_text[i] + " "), e.args)
	
	print("Waiting for {} secs".format(WAIT))
	time.sleep(WAIT)
	print("Wait complete")

'''
Post processing
'''
with open(OUTPUT_FILE, 'r') as file:
  en_text = file.read()

en_text = en_text.replace('\\\'', '\'')
en_text = en_text.replace('\'', '\\\'')

en_text = en_text.replace('\\ n', '\\n')
en_text = en_text.replace(' \\n', '\\n')
en_text = en_text.replace('\\n ', '\\n')
en_text = en_text.replace(' \\n ', '\\n')

en_text = en_text.replace('\\ N', '\\n')
en_text = en_text.replace(' \\N', '\\n')
en_text = en_text.replace('\\N ', '\\n')
en_text = en_text.replace(' \\N ', '\\n')

en_text = en_text.replace('%% s', '%s')
en_text = en_text.replace(' / ', '/')
en_text = en_text.replace(' \\ ', '\\')

en_text = en_text.replace('& lt; ', '&lt;')
en_text = en_text.replace('& lt;', '&lt;')
en_text = en_text.replace(' & gt;', '&gt;')
en_text = en_text.replace('& gt;', '&gt;')

en_text = en_text.replace(' % ', '%')
en_text = en_text.replace('% ', '%')
en_text = en_text.replace(' %', '%')
en_text = en_text.replace(' $ ', '$')
en_text = en_text.replace('$ ', '$')
en_text = en_text.replace(' $', '$')
en_text = en_text.replace('&', '&amp;')

en_text = en_text.replace(' < ', '<')
en_text = en_text.replace(' <', '<')
en_text = en_text.replace('< ', '<')
en_text = en_text.replace(' </ ', '</')
en_text = en_text.replace(' </', '</')
en_text = en_text.replace('</ ', '</')
en_text = en_text.replace(' > ', '>')
en_text = en_text.replace('> ', '>')
en_text = en_text.replace(' >', '>')

with open(OUTPUT_FILE, 'w') as file:
  file.write(en_text)

print("Post processing done!")