Adding meli.expires_in (I found it rather useful)
Applying PEP-8 (http://www.python.org/dev/peps/pep-0008/):
meli.py:11:1: E302 expected 2 blank lines, found 1
meli.py:12:80: E501 line too long (88 > 79 characters)
meli.py:17:31: W291 trailing whitespace
meli.py:28:22: E231 missing whitespace after ','
meli.py:29:30: E231 missing whitespace after ':'
meli.py:29:45: E231 missing whitespace after ','
meli.py:29:61: E231 missing whitespace after ':'
meli.py:29:68: E231 missing whitespace after ','
meli.py:29:80: E501 line too long (96 > 79 characters)
meli.py:29:83: E231 missing whitespace after ':'
meli.py:30:28: E221 multiple spaces before operator
meli.py:34:19: E201 whitespace after '{'
meli.py:34:32: E203 whitespace before ':'
meli.py:34:68: E203 whitespace before ':'
meli.py:34:80: E501 line too long (169 > 79 characters)
meli.py:34:102: E203 whitespace before ':'
meli.py:34:131: E203 whitespace before ':'
meli.py:34:154: E203 whitespace before ':'
meli.py:35:62: E231 missing whitespace after ':'
meli.py:35:80: E501 line too long (114 > 79 characters)
meli.py:35:95: E231 missing whitespace after ':'
meli.py:38:80: E501 line too long (80 > 79 characters)
meli.py:46:40: E261 at least two spaces before inline comment
meli.py:56:35: E203 whitespace before ':'
meli.py:56:66: E203 whitespace before ':'
meli.py:56:80: E501 line too long (159 > 79 characters)
meli.py:56:100: E203 whitespace before ':'
meli.py:56:138: E203 whitespace before ':'
meli.py:57:66: E231 missing whitespace after ':'
meli.py:57:80: E501 line too long (118 > 79 characters)
meli.py:57:99: E231 missing whitespace after ':'
meli.py:60:80: E501 line too long (97 > 79 characters)
meli.py:72:28: W602 deprecated form of raising exception
meli.py:76:62: E231 missing whitespace after ':'
meli.py:76:80: E501 line too long (114 > 79 characters)
meli.py:76:95: E231 missing whitespace after ':'
meli.py:82:62: E231 missing whitespace after ':'
meli.py:82:80: E501 line too long (114 > 79 characters)
meli.py:82:95: E231 missing whitespace after ':'
meli.py:87:80: E501 line too long (91 > 79 characters)
meli.py:91:62: E231 missing whitespace after ':'
meli.py:91:80: E501 line too long (114 > 79 characters)
meli.py:91:95: E231 missing whitespace after ':'
meli.py:96:80: E501 line too long (90 > 79 characters)
meli.py:100:62: E231 missing whitespace after ':'
meli.py:100:80: E501 line too long (114 > 79 characters)
meli.py:100:95: E231 missing whitespace after ':'
meli.py:106:62: E231 missing whitespace after ':'
meli.py:106:80: E501 line too long (114 > 79 characters)
meli.py:106:95: E231 missing whitespace after ':'
meli.py:108:80: E501 line too long (83 > 79 characters)