"ValueError: Invalid control character" using Python OAuth client - python-2.7

Question

I am trying to load data from a google spreadsheet into a postgres database.
The problem is when I am trying to authenticate my credentials, I get the following error:
File "/usr/local/lib/python2.7/dist-packages/oauth2client/_openssl_crypt.py", line 117, in from_string
pkey = crypto.load_privatekey(crypto.FILETYPE_PEM, parsed_pem_key)
OpenSSL.crypto.Error: [('PEM routines', 'PEM_read_bio', 'no start line')]
I have followed all steps in Using OAuth2 for Authorization, enabled the API and created a service account from which I got a .json file containing the necessary keys and authentication elements.
The way I am trying to authenticate is the following:
json_key = json.load(open('gdoc.json'),strict=False)
creds = SignedJwtAssertionCredentials(json_key['client_email'], json_key['private_key'], scope)
login = gspread.authorize(creds)
Perhaps the issue comes from the parameter in the json load strict=False, the problem is if I remove it, get the error:
File "/usr/lib/python2.7/json/decoder.py", line 382, in raw_decode
obj, end = self.scan_once(s, idx)
ValueError: Invalid control character at: line 5 column 38 (char 174)
I saw a couple other forums and they suggest using the strict=False parameter since there are non escaped \n inside the json key file.
This is a copy of the .json key file:
{
"type": "service_account",
"project_id": "geometric-shine-118101",
"private_key_id": "xxx",
"private_key": "-----BEGIN PRIVATE KEY-----\nxxx\n-----END PRIVATE KEY-----\n",
"client_email": "dataload#geometric-shine-118101.iam.gserviceaccount.com",
"client_id": "117076930343404252458",
"auth_uri": "https://accounts.google.com/o/oauth2/auth",
"token_uri": "https://accounts.google.com/o/oauth2/token",
"auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
"client_x509_cert_url": "https://www.googleapis.com/robot/v1/metadata/x509/dataload%40geometric-shine-118101.iam.gserviceaccount.com"
}

Answer 1

"private_key": "-----BEGIN PRIVATE KEY-----\nxxx\n-----END PRIVATE KEY-----\n",
"client_email": "dataload#geometric-shine-118101.iam.gserviceaccount.com",
Copy and paste the actual values into single quotes (.e.g. ''). It worked for me.
'dataload#geometric-shine-118101.iam.gserviceaccount.com'
'-----BEGIN PRIVATE KEY-----\nxxx\n-----END PRIVATE KEY-----\n'