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"""Utilities to manipulate JSON objects."""
# Copyright (c) Jupyter Development Team.
# Distributed under the terms of the Modified BSD License.
import math
import numbers
import re
import types
import warnings
from binascii import b2a_base64
from collections.abc import Iterable
from datetime import datetime
from typing import Any, Optional, Union
from dateutil.parser import parse as _dateutil_parse
from dateutil.tz import tzlocal
next_attr_name = "__next__" # Not sure what downstream library uses this, but left it to be safe
# -----------------------------------------------------------------------------
# Globals and constants
# -----------------------------------------------------------------------------
# timestamp formats
ISO8601 = "%Y-%m-%dT%H:%M:%S.%f"
ISO8601_PAT = re.compile(
r"^(\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2})(\.\d{1,6})?(Z|([\+\-]\d{2}:?\d{2}))?$"
)
# holy crap, strptime is not threadsafe.
# Calling it once at import seems to help.
datetime.strptime("1", "%d") # noqa
# -----------------------------------------------------------------------------
# Classes and functions
# -----------------------------------------------------------------------------
def _ensure_tzinfo(dt: datetime) -> datetime:
"""Ensure a datetime object has tzinfo
If no tzinfo is present, add tzlocal
"""
if not dt.tzinfo:
# No more naïve datetime objects!
warnings.warn(
"Interpreting naive datetime as local %s. Please add timezone info to timestamps." % dt,
DeprecationWarning,
stacklevel=4,
)
dt = dt.replace(tzinfo=tzlocal())
return dt
def parse_date(s: Optional[str]) -> Optional[Union[str, datetime]]:
"""parse an ISO8601 date string
If it is None or not a valid ISO8601 timestamp,
it will be returned unmodified.
Otherwise, it will return a datetime object.
"""
if s is None:
return s
m = ISO8601_PAT.match(s)
if m:
dt = _dateutil_parse(s)
return _ensure_tzinfo(dt)
return s
def extract_dates(obj: Any) -> Any:
"""extract ISO8601 dates from unpacked JSON"""
if isinstance(obj, dict):
new_obj = {} # don't clobber
for k, v in obj.items():
new_obj[k] = extract_dates(v)
obj = new_obj
elif isinstance(obj, (list, tuple)):
obj = [extract_dates(o) for o in obj]
elif isinstance(obj, str):
obj = parse_date(obj)
return obj
def squash_dates(obj: Any) -> Any:
"""squash datetime objects into ISO8601 strings"""
if isinstance(obj, dict):
obj = dict(obj) # don't clobber
for k, v in obj.items():
obj[k] = squash_dates(v)
elif isinstance(obj, (list, tuple)):
obj = [squash_dates(o) for o in obj]
elif isinstance(obj, datetime):
obj = obj.isoformat()
return obj
def date_default(obj: Any) -> Any:
"""DEPRECATED: Use jupyter_client.jsonutil.json_default"""
warnings.warn(
"date_default is deprecated since jupyter_client 7.0.0."
" Use jupyter_client.jsonutil.json_default.",
stacklevel=2,
)
return json_default(obj)
def json_default(obj: Any) -> Any:
"""default function for packing objects in JSON."""
if isinstance(obj, datetime):
obj = _ensure_tzinfo(obj)
return obj.isoformat().replace("+00:00", "Z")
if isinstance(obj, bytes):
return b2a_base64(obj, newline=False).decode("ascii")
if isinstance(obj, Iterable):
return list(obj)
if isinstance(obj, numbers.Integral):
return int(obj)
if isinstance(obj, numbers.Real):
return float(obj)
raise TypeError("%r is not JSON serializable" % obj)
# Copy of the old ipykernel's json_clean
# This is temporary, it should be removed when we deprecate support for
# non-valid JSON messages
def json_clean(obj: Any) -> Any:
# types that are 'atomic' and ok in json as-is.
atomic_ok = (str, type(None))
# containers that we need to convert into lists
container_to_list = (tuple, set, types.GeneratorType)
# Since bools are a subtype of Integrals, which are a subtype of Reals,
# we have to check them in that order.
if isinstance(obj, bool):
return obj
if isinstance(obj, numbers.Integral):
# cast int to int, in case subclasses override __str__ (e.g. boost enum, #4598)
return int(obj)
if isinstance(obj, numbers.Real):
# cast out-of-range floats to their reprs
if math.isnan(obj) or math.isinf(obj):
return repr(obj)
return float(obj)
if isinstance(obj, atomic_ok):
return obj
if isinstance(obj, bytes):
# unanmbiguous binary data is base64-encoded
# (this probably should have happened upstream)
return b2a_base64(obj, newline=False).decode("ascii")
if isinstance(obj, container_to_list) or (
hasattr(obj, "__iter__") and hasattr(obj, next_attr_name)
):
obj = list(obj)
if isinstance(obj, list):
return [json_clean(x) for x in obj]
if isinstance(obj, dict):
# First, validate that the dict won't lose data in conversion due to
# key collisions after stringification. This can happen with keys like
# True and 'true' or 1 and '1', which collide in JSON.
nkeys = len(obj)
nkeys_collapsed = len(set(map(str, obj)))
if nkeys != nkeys_collapsed:
msg = (
"dict cannot be safely converted to JSON: "
"key collision would lead to dropped values"
)
raise ValueError(msg)
# If all OK, proceed by making the new dict that will be json-safe
out = {}
for k, v in obj.items():
out[str(k)] = json_clean(v)
return out
if isinstance(obj, datetime):
return obj.strftime(ISO8601)
# we don't understand it, it's probably an unserializable object
raise ValueError("Can't clean for JSON: %r" % obj)
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