def _request(self, n, k):
"""Constructs the query string for this :class:`Query` object for the
specified paging limits and then returns the response from the REST API
as a python object.
Args:
n (int): page number of the results to return.
k (int): number of datasets per page.
"""
if len(self.responses) == 0:
#We are making the very first request, finalize the query.
self.finalize()
import json
from six.moves import urllib
urlopen = urllib.request.urlopen
url = "{0}{1},{2}".format(server, self.matchbook(),
self._directives(n, k))
rawresp = urlopen(url).read().decode("utf-8")
try:
response = json.loads(rawresp)
except: # pragma: no cover
#We can't easily simulate network failure...
msg.err("{}\n\n{}".format(url, rawresp))
return
#If this is the first request, then save the number of results in the
#query.
if len(self.responses) == 0:
self._N = int(next(iter(response.keys())).split()[-1])
self.responses[n] = response
def _get_response(url, session=None, page=None):
"""
Retrieve JSON data from URL with retries.
Args:
url (str): url to retrieve
session (requests.Session): optional, a Session object to
perform the request
page (int): optional, metadata holding the page number of the request.
Useful when this method is called using a thread pool.
Returns:
tuple: if page is specified, (is_ok, response, page), otherwise (is_ok, response),
where `is_ok` is True if the request completed successfully, False otherwise,
`response` contains the JSON response or the error information if the request
was unsuccessful, `page` is the page number metadata.
"""
if not session:
session = requests.Session()
retries = Retry(total=5, backoff_factor=10, status_forcelist=[500], connect=0)
session.mount('http://', HTTPAdapter(max_retries=retries))
try:
rawresp = session.get(url)
is_ok = rawresp.ok
response = rawresp.json()
except (ReqConnError, RetryError) as ex: # pragma: no cover
is_ok = False
response = ex.args
_msg.err("{}\n\n{}".format(url, response))
if page is not None:
return is_ok, response, page
return is_ok, response
def _check_input(string):
"""Check if the input string contains invalid string"""
forbidden_chars = (
'"',
"@",
"\\",
"~",
"/",
) # characters that will cause LUX crash
if any([c in string for c in forbidden_chars]):
msg.err(
f"Input {string} contains one or more of the forbidden characters: {forbidden_chars}"
)
return False
else:
return True
def cast(atype, keyword, value):
"""Casts the specified value to a python type, using the AFLOW type as a
reference.
.. note:: Unfortunately, some of the AFLOW type names are not descriptive or
unique enough to make general rule casting possible. Instead, we have to
encode some exceptions directly in this module.
Args:
atype (str): name of the AFLOW type.
keyword (str): name of the keyword that the value is associated with.
value: object (usually a string) to cast into python types.
"""
if value is None:
return
castmap = {
"string": str,
"strings": _strings,
"number": _number,
"numbers": _numbers,
"forces": _forces,
"kpoints": _kpoints,
"positions_cartesian": _forces,
"positions_fractional": _forces,
"spind": _numbers,
"stoich": _stoich,
"ldau_TLUJ": _ldau_TLUJ,
"None": lambda v: v,
None: lambda v: v,
}
try:
if keyword not in exceptions:
return castmap[atype](value)
else:
return castmap[keyword](value)
except:
msg.err("Cannot cast {}; unknown format.".format(value))
def set_manual_matchbook(self, matchbook):
"""Statelessly set the matchbook string part of the aflow query
set the self._matchbook to matchbook and make it final
matchbook should be a string.
The method does not enforce type check.
Use it only when the default keyword method messes up
"""
if not isinstance(matchbook, str):
msg.err(
(f"Manual input query must be a string, not {type(matchbook)}."
"The matchbook is not set"))
self._matchbook = None
self._final = False
return self
if _check_input(matchbook):
self._matchbook = matchbook
self._final = True
else:
self._matchbook = None
return self
def filter(self, keyword):
"""Adds a search term to the current filter list. Calling :meth:`filter`
multiple times will join the final filters together using logical *and*.
Args:
keyword (aflow.keywords.Keyword): that encapsulates the AFLUX
request language logic.
New version: allowing keyword as a single string containing filters
"""
if self._final_check():
self._N = None
if isinstance(keyword, str): # normal string
if _check_input(keyword):
self.filters.append(keyword)
elif hasattr(keyword, "func"): # Is a sympy symbol
expr = _expr_to_strings(keyword)
self.filters.append(expr)
else:
msg.err(("Query.filter() takes either "
"boolean expression or string,"
f" not {type(keyword)}"))
return self
