Make codebase compatible with Python 3.7

great_ai/large_file/helper/__init__.py

@@ -1,2 +1,3 @@
+from .cached_property import cached_property
 from .human_readable_to_byte import human_readable_to_byte
 from .progress_bar import DownloadProgressBar, UploadProgressBar

great_ai/large_file/helper/cached_property.py

@@ -0,0 +1,52 @@
+from threading import RLock
+
+_NOT_FOUND = object()
+
+
+class cached_property:
+    def __init__(self, func):  # type: ignore
+        self.func = func
+        self.attrname = None
+        self.__doc__ = func.__doc__
+        self.lock = RLock()
+
+    def __set_name__(self, owner, name):  # type: ignore
+        if self.attrname is None:
+            self.attrname = name
+        elif name != self.attrname:
+            raise TypeError(
+                "Cannot assign the same cached_property to two different names "
+                f"({self.attrname!r} and {name!r})."
+            )
+
+    def __get__(self, instance, owner=None):  # type: ignore
+        if instance is None:
+            return self
+        if self.attrname is None:
+            raise TypeError(
+                "Cannot use cached_property instance without calling __set_name__ on it."
+            )
+        try:
+            cache = instance.__dict__
+        except AttributeError:  # not all objects have __dict__ (e.g. class defines slots)
+            msg = (
+                f"No '__dict__' attribute on {type(instance).__name__!r} "
+                f"instance to cache {self.attrname!r} property."
+            )
+            raise TypeError(msg) from None
+        val = cache.get(self.attrname, _NOT_FOUND)
+        if val is _NOT_FOUND:
+            with self.lock:
+                # check if another thread filled cache while we awaited lock
+                val = cache.get(self.attrname, _NOT_FOUND)
+                if val is _NOT_FOUND:
+                    val = self.func(instance)
+                    try:
+                        cache[self.attrname] = val
+                    except TypeError:
+                        msg = (
+                            f"The '__dict__' attribute on {type(instance).__name__!r} instance "
+                            f"does not support item assignment for caching {self.attrname!r} property."
+                        )
+                        raise TypeError(msg) from None
+        return val

great_ai/large_file/large_file/large_file_base.py

@@ -1,5 +1,6 @@
 import os
 import shutil
+import sys
 import tempfile
 from abc import ABC, abstractmethod
 from functools import lru_cache
@@ -70,7 +71,13 @@ class LargeFileBase(ABC):
 
         self._buffering = buffering
         self._encoding = encoding
+
+        if errors is not None and sys.version_info[1] < 8:
+            raise RuntimeError(
+                "The `errors` kwarg is only supported in 3.8 <= Python versions."
+            )
         self._errors = errors
+
         self._newline = newline
 
         LargeFileBase.cache_path.mkdir(parents=True, exist_ok=True)
@@ -99,16 +106,20 @@ class LargeFileBase(ABC):
         cls.initialized = True
 
     def __enter__(self) -> IO:
+        params = dict(
+            mode=self._mode,
+            buffering=self._buffering,
+            encoding=self._encoding,
+            newline=self._newline,
+            delete=False,
+            prefix="large_file-",
+        )
+
+        if sys.version_info[1] >= 8:
+            params["errors"] = self._errors
+
         self._file: IO[Any] = (
-            tempfile.NamedTemporaryFile(
-                mode=self._mode,
-                buffering=self._buffering,
-                encoding=self._encoding,
-                newline=self._newline,
-                errors=self._errors,
-                delete=False,
-                prefix="large_file-",
-            )
+            tempfile.NamedTemporaryFile(**params)  # type: ignore
             if "w" in self._mode
             else open(
                 self.get(),

great_ai/large_file/large_file/large_file_mongo.py

@@ -1,5 +1,4 @@
 import re
-from functools import cached_property
 from pathlib import Path
 from typing import Any, List
 
@@ -7,7 +6,7 @@ from gridfs import DEFAULT_CHUNK_SIZE, Database, GridFSBucket
 from pymongo import MongoClient
 
 from ...utilities import get_logger
-from ..helper import DownloadProgressBar, UploadProgressBar
+from ..helper import DownloadProgressBar, UploadProgressBar, cached_property
 from ..models import DataInstance
 from .large_file_base import LargeFileBase
 

great_ai/large_file/large_file/large_file_s3.py

@@ -1,11 +1,10 @@
-from functools import cached_property
 from pathlib import Path
 from typing import Any, List, Optional
 
 import boto3
 
 from ...utilities import get_logger
-from ..helper import DownloadProgressBar, UploadProgressBar
+from ..helper import DownloadProgressBar, UploadProgressBar, cached_property
 from ..models import DataInstance
 from .large_file_base import LargeFileBase