The following piece of code works in 3.6.1 but does not work in 3.6.4.
### myscript.py
import requests
from lxml import etree
XSD_URL = 'http://ops.epo.org/3.1/schema/ops.xsd'
CONTENT_URL = 'http://ops.epo.org/3.1/rest-services/published-data/publication/epodoc/WO0045222/full-cycle'
schema = etree.XMLSchema(etree=etree.XML(requests.get(XSD_URL).content, base_url='http://ops.epo.org/3.1/schema/'))
parser = etree.XMLParser(schema=schema)
root = etree.fromstring(requests.get(CONTENT_URL).content, parser)
###
Scenario 1 (not working)
===
Python : sys.version_info(major=2, minor=7, micro=12, releaselevel='final', serial=0)
lxml.etree : (3, 6, 4, 0)
libxml used : (2, 9, 4)
libxml compiled : (2, 9, 4)
libxslt used : (1, 1, 29)
libxslt compiled : (1, 1, 29)
Script output:
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "src/lxml/lxml.etree.pyx", line 3213, in lxml.etree.fromstring (src/lxml/lxml.etree.c:77737)
File "src/lxml/parser.pxi", line 1830, in lxml.etree._parseMemoryDocument (src/lxml/lxml.etree.c:116674)
File "src/lxml/parser.pxi", line 1718, in lxml.etree._parseDoc (src/lxml/lxml.etree.c:115324)
File "src/lxml/parser.pxi", line 1090, in lxml.etree._BaseParser._parseDoc (src/lxml/lxml.etree.c:109723)
File "src/lxml/parser.pxi", line 584, in lxml.etree._ParserContext._handleParseResultDoc (src/lxml/lxml.etree.c:103584)
File "src/lxml/parser.pxi", line 694, in lxml.etree._handleParseResult (src/lxml/lxml.etree.c:105238)
File "src/lxml/parser.pxi", line 624, in lxml.etree._raiseParseError (src/lxml/lxml.etree.c:104147)
lxml.etree.XMLSyntaxError: Element '{http://www.epo.org/exchange}exchange-document', attribute 'country': [facet 'enumeration'] The value '' is not an element of the set {'AD', 'AE', 'AF', 'AG', 'AI', 'AL', 'AM', 'AN', 'AO', 'AP', 'AQ', 'AR', 'AS', 'AT', 'AU', 'AW', 'AZ', 'BA', 'BB', 'BD', 'BE', 'BF', 'BG', 'BH', 'BI', 'BJ', 'BM', 'BN', 'BO', 'BR', 'BS', 'BT', 'BU', 'BV', 'BW', 'BX', 'BY', 'BZ', 'CA', 'CC', 'CD', 'CF', 'CG', 'CH', 'CI', 'CK', 'CL', 'CM', 'CN', 'CO', 'CR', 'CS', 'CT', 'CU', 'CV', 'CX', 'CY', 'CZ', 'DD', 'DE', 'DJ', 'DK', 'DM', 'DO', 'DY', 'DZ', 'EA', 'EC', 'EE', 'EG', 'EH', 'EM', 'EP', 'ER', 'ES', 'ET', 'FI', 'FJ', 'FK', 'FM', 'FO', 'FR', 'FX', 'GA', 'GB', 'GC', 'GD', 'GE', 'GF', 'GH', 'GI', 'GL', 'GM', 'GN', 'GP', 'GQ', 'GR', 'GS', 'GT', 'GU', 'GW', 'GY', 'HK', 'HM', 'HN', 'HR', 'HT', 'HU', 'HV', 'IB', 'ID', 'IE', 'IL', 'IN', 'IO', 'IQ', 'IR', 'IS', 'IT', 'JM', 'JO', 'JP', 'JT', 'KE', 'KG', 'KH', 'KI', 'KM', 'KN', 'KP', 'KR', 'KW', 'KY', 'KZ', 'LA', 'LB', 'LC', 'LI', 'LK', 'LR', 'LS', 'LT', 'LU', 'LV', 'LY', 'MA', 'MC', 'MD', 'ME', 'MG', 'MH', 'MI', 'MK', 'ML', 'MM', 'MN', 'MO', 'MP', 'MQ', 'MR', 'MS', 'MT', 'MU', 'MV', 'MW', 'MX', 'MY', 'MZ', 'NA', 'NC', 'NE', 'NF', 'NG', 'NH', 'NI', 'NL', 'NO', 'NP', 'NQ', 'NR', 'NT', 'NU', 'NZ', 'OA', 'OM', 'PA', 'PC', 'PE', 'PF', 'PG', 'PH', 'PK', 'PL', 'PM', 'PN', 'PR', 'PT', 'PU', 'PW', 'PY', 'PZ', 'QA', 'RE', 'RH', 'RO', 'RS', 'RU', 'RW', 'SA', 'SB', 'SC', 'SD', 'SE', 'SG', 'SH', 'SI', 'SJ', 'SK', 'SL', 'SM', 'SN', 'SO', 'SR', 'ST', 'SU', 'SV', 'SY', 'SZ', 'TC', 'TD', 'TF', 'TG', 'TH', 'TJ', 'TK', 'TM', 'TN', 'TO', 'TP', 'TR', 'TT', 'TV', 'TW', 'TZ', 'UA', 'UG', 'UM', 'US', 'UY', 'UZ', 'VA', 'VC', 'VD', 'VE', 'VG', 'VI', 'VN', 'VU', 'WF', 'WO', 'WS', 'XH', 'YD', 'YE', 'YT', 'YU', 'ZA', 'ZM', 'ZR', 'ZW'}.
Scenario 2 (working)
===
Python : sys.version_info(major=2, minor=7, micro=12, releaselevel='final', serial=0)
lxml.etree : (3, 6, 1, 0)
libxml used : (2, 9, 3)
libxml compiled : (2, 9, 3)
libxslt used : (1, 1, 28)
libxslt compiled : (1, 1, 28)
Script output:
<empty>
Discussion
===
In fact, analyzing the content, the "country" attribute of "exchange-document" contains a value in the list (namely, "WO").
The error started occurring when updated to 3.6.4.
