def get(self, *keys, default=None, cast=None):
''' str ..., maybe any, maybe any -> any | DatabaseError
retrieve a given key, if the key is not found `default` will be
returned instead
>>> values = db.get('nonexistant', 'index', default={})
>>> type(values)
dict
>>> values = db.get('index', 'that', 'exists', cast=set)
>>> type(values)
set
'''
keys = list(keys) if keys else ['']
result = self.query(keys, interpret=True)
if not result:
return default
if cast:
try:
if not isinstance(result, (list, dict,)):
result = [result]
return cast(result)
except ValueError:
raise DatabaseError(
'error: unable to case to ' + str(cast)) from None
return result
def _query(args, host='localhost', port=9999, interpret=False,
close=True, sock=None):
''' list of str, str, int, bool, bool, bool -> any
the real query function, all the others are wrappers
send a query to an Apocrypha server, either returning a list of strs or
the result of json.loads() on the result
'''
args = list(args)
remote = (host, port)
if interpret and args and args[-1] not in {'-e', '--edit'}:
args += ['--edit']
message = '\n'.join(args) + '\n'
# if they didn't give us a socket create a new one
if not sock:
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect(remote)
# send the message, get the reply using apocrypha.network calls
write(sock, message)
result, error = read(sock)
if error:
sock.close()
sock = None
raise DatabaseError('error: network length')
if close:
sock.close()
result = list(filter(None, result.split('\n')))
if result and result[0].startswith('error: '):
raise DatabaseError(result[0]) from None
if interpret:
result = json.loads(''.join(result)) if result else None
return result, sock
def _error(self, message: str) -> None:
'''
@message description of the error that occurred
#impure self.output
Send an error to the user and stop execution. In headless mode, errors
are appended to the class.output list
'''
message = 'error: ' + message
if self.headless:
self.output += [message]
raise DatabaseError(message + '\n')
print(message, file=sys.stderr)
sys.exit(1)
def remove(self, *keys, value):
''' str ..., str | list of str -> none | DatabaseError
remove an element from a list, if more than one of the element exists
in the list, only one is removed
>>> db.set('my', 'list', value=['a', 'b', 'c'])
>>> db.remove('my', 'list', value='b')
'''
keys = list(keys) if keys else ['']
if isinstance(value, str):
value = [value]
if not isinstance(value, (str, list)):
raise DatabaseError('error: {v} is not a str or list') from None
self.query(keys + ['-'] + value)
def pop(self, *keys, cast=None):
''' str ... -> any | None
'''
keys = list(keys) if keys else ['']
result = self.query(keys + ['--pop'])
result = result[0] if result else None
try:
if result and cast:
result = cast(result)
except ValueError:
raise DatabaseError(
'error: cast {c} is not applicable to {t}'
.format(c=cast.__name__, t=result)) from None
return result
def set(self, *keys, value):
''' str ..., str | list | dict | none -> none
set a value for a given key, creating if necessary. can be used to
delete keys if value={}
>>> events = {'key': 'value'}
>>> db.set('devbot', 'events', value=events)
>>> db.get('devbot', 'events')
{'key': 'value'}
'''
keys = list(keys) if keys else ['']
try:
value = json.dumps(value)
self.query(keys + ['--set', value])
except (TypeError, ValueError):
raise DatabaseError(
'error: value is not JSON serializable') from None
def append(self, *keys, value):
''' str ..., str | list of str -> none | DatabaseError
append an element to an apocrypha list. appending to a str creates a
list with the original element and the new element
>>> db.append('new key', value='hello')
>>> type(db.get('new key'))
str
>>> db.append('new key', value='there')
>>> type(db.get('new key'))
list
'''
keys = list(keys) if keys else ['']
if isinstance(value, str):
value = [value]
try:
self.query(keys + ['+'] + value)
except (TypeError, ValueError):
raise DatabaseError('error: {v} is not a str or list') from None