Guard dxpy imports so dnanexus and swift can actually be optional

docs/release_notes.rst

@@ -1,6 +1,10 @@
 Release Notes
 =============
 
+v4.2.0
+------
+* Guard dxpy imports in utils so you can use stor without either dxpy or swift installed. (#143)
+
 v4.1.0
 ------
 * Replace ``multiprocessing.ThreadPool`` with ``concurrent.futures.ThreadPoolExecutor``

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "stor"
-version = "4.1.0"
+version = "4.2.0"
 description = "Cross-compatible API for accessing Posix and OBS storage systems"
 authors = ["Counsyl Inc. <opensource@counsyl.com>"]
 license = "MIT"

stor/obs.py

@@ -3,10 +3,6 @@
 import posixpath
 import sys
 
-import dxpy
-from swiftclient.service import SwiftError
-from swiftclient.service import SwiftUploadObject
-
 from stor.base import Path
 from stor.posix import PosixPath
 from stor import utils
@@ -28,6 +24,17 @@ def wrapper(self, *args, **kwargs):
     return wrapper
 
 
+try:
+    from swiftclient.service import SwiftUploadObject
+except ImportError:  # pragma: no cover
+    class SwiftUploadObject(object):
+        """Give 90% of the utility of SwiftUploadObject class without swiftclient!"""
+        def __init__(self, source, object_name=None, options=None):
+            self.source = source
+            self.object_name = object_name
+            self.options = options
+
+
 class OBSUploadObject(SwiftUploadObject):
     """
     An upload object similar to swiftclient's SwiftUploadObject that allows the user
@@ -41,6 +48,8 @@ def __init__(self, source, object_name, options=None):
             source (str): A path that specifies a source file.
             dest (str): A path that specifies a destination file name (full key)
         """
+        from swiftclient.service import SwiftError
+
         try:
             super(OBSUploadObject, self).__init__(source, object_name=object_name, options=options)
         except SwiftError as exc:
@@ -452,6 +461,8 @@ def close(self):
         self.closed = True
 
     def _wait_on_close(self):
+        import dxpy
+
         if isinstance(self._path, stor.dx.DXPath):
             wait_on_close = stor.settings.get()['dx']['wait_on_close']
             if wait_on_close:

stor/utils.py

@@ -8,9 +8,6 @@
 from subprocess import check_call
 import tempfile
 
-from dxpy.bindings import verify_string_dxid
-from dxpy.exceptions import DXError
-
 from stor import exceptions
 
 logger = logging.getLogger(__name__)
@@ -190,8 +187,7 @@ def is_swift_path(p):
     Returns:
         bool: True if p is a Swift path, False otherwise.
     """
-    from stor.swift import SwiftPath
-    return p.startswith(SwiftPath.drive)
+    return p.startswith('swift://')
 
 
 def is_filesystem_path(p):
@@ -217,8 +213,7 @@ def is_s3_path(p):
     Returns
         bool: True if p is a S3 path, False otherwise.
     """
-    from stor.s3 import S3Path
-    return p.startswith(S3Path.drive)
+    return p.startswith('s3://')
 
 
 def is_obs_path(p):
@@ -244,8 +239,7 @@ def is_dx_path(p):
     Returns
         bool: True if p is a DX path, False otherwise.
     """
-    from stor.dx import DXPath
-    return p.startswith(DXPath.drive)
+    return p.startswith('dx://')
 
 
 def is_valid_dxid(dxid, expected_classes):
@@ -257,6 +251,9 @@ def is_valid_dxid(dxid, expected_classes):
     Returns
         bool: Whether given dxid is a valid path of one of expected_classes
     """
+    from dxpy.bindings import verify_string_dxid
+    from dxpy.exceptions import DXError
+
     try:
         return verify_string_dxid(dxid, expected_classes) is None
     except DXError: