Input length validation may be inaccurate.

[Vincent-Stragier]

Hi @snjv94,

Looking at the code, I'd say the error is still due to the length of the string. At the moment, the code is checking for a number of characters in a string (here 1701 and 2053), which here is lower than the number of bytes (here 5035 and 6091). So it passes the condition but failed to receive a valid response from the API. By chance, you still received an answer for the shortest sample, even if it seems it is slightly oversize bitwise.

Note: in my case at first I received None as an answer for the shortest sample string; because you forgot the return statement in you function.

deep-translator/deep_translator/google.py

Lines 51 to 75 in fa67ada

	def translate(self, text: str, **kwargs) -> str:
	"""
	function to translate a text
	@param text: desired text to translate
	@return: str: translated text
	"""
	if is_input_valid(text, max_chars=5000):
	text = text.strip()
	if self._same_source_target() or is_empty(text):
	return text
	self._url_params["tl"] = self._target
	self._url_params["sl"] = self._source
	if self.payload_key:
	self._url_params[self.payload_key] = text
	response = requests.get(
	self._base_url, params=self._url_params, proxies=self.proxies
	)
	if response.status_code == 429:
	raise TooManyRequests()
	if request_failed(status_code=response.status_code):
	raise RequestError()

As we can see here, len(text) is used and text is a string:

deep-translator/deep_translator/validate.py

Lines 27 to 43 in fa67ada

	def is_input_valid(
	text: str, min_chars: int = 0, max_chars: Optional[int] = None
	) -> bool:
	"""
	validate the target text to translate
	@param min_chars: min characters
	@param max_chars: max characters
	@param text: text to translate
	@return: bool
	"""
	if not isinstance(text, str):
	raise NotValidPayload(text)
	if max_chars and (not min_chars <= len(text) < max_chars):
	raise NotValidLength(text, min_chars, max_chars)
	return True

A way to solve this issue is probably to use the string encode method to encode the string in UTF-8 as an array of bytes. In the Python documentation about Unicode, we can read the following snippet:

>>> u = chr(40960) + 'abcd' + chr(1972)
>>> u.encode('utf-8')
b'\xea\x80\x80abcd\xde\xb4'
>>> u.encode('ascii')  
Traceback (most recent call last):
    ...
UnicodeEncodeError: 'ascii' codec can't encode character '\ua000' in
  position 0: ordinal not in range(128)
>>> u.encode('ascii', 'ignore')
b'abcd'
>>> u.encode('ascii', 'replace')
b'?abcd?'
>>> u.encode('ascii', 'xmlcharrefreplace')
b'ꀀabcd޴'
>>> u.encode('ascii', 'backslashreplace')
b'\\ua000abcd\\u07b4'
>>> u.encode('ascii', 'namereplace')
b'\\N{YI SYLLABLE IT}abcd\\u07b4'

Which makes me believe len(text) should be replaced by len(text.encode('UTF-8", "ignore") or len(text.encode('UTF-8", "xmlcharrefreplace"). And, maybe return the size for the string and bytes for the user when raising the error.

Thanks for the assistance, @Vincent-Stragier

Originally posted by @snjv94 in #169 (comment)

[TrexPD]

So if I understand correctly, it would be enough to use:

text_bytes = text.encode('utf-8')
if max_chars and (not min_chars <= len(text_bytes) < max_chars):
    raise NotValidLength(text, min_chars, max_chars)"```

[Vincent-Stragier]

I would use the following to avoid raising an encoding error:

text_bytes = text.encode('utf-8', "ignore")
# or
text_bytes = text.encode('utf-8', "replace")
# or
# probably better to avoid getting an underestimated size (still not perfect).
text_bytes = text.encode('UTF-8", "xmlcharrefreplace")  

if max_chars and (not min_chars <= len(text_bytes) < max_chars):
    raise NotValidLength(text, min_chars, max_chars)"