Support configurable settings directory with lazy initialization (#1195)

This PR makes 2 changes to our handling of the .plotly settings directory.

 1. The default location of this directory is still ~/.plotly, but it can now be overridden by setting the PLOTLY_DIR environment variable before Python starts.
 2. Previously this settings directory was created and initialized during the initial import of the plotly library. Now, the creation of the directory and the initialization of the configuration files is delayed until an operation is performed that needs to write to the directory. Defaults are now returned when settings are accessed and the config directory does not exist.

Change 1 provides a way to customize the location of plotly.py's settings, and makes it possible for users to create and maintain multiple profiles.

Change 2 removes the concurrency issues associated with launching many plotly processes simultaneously.

Author: jonmmease

Diff for: plotly/files.py

@@ -1,10 +1,11 @@
 import os
 
 # file structure
-PLOTLY_DIR = os.path.join(os.path.expanduser("~"), ".plotly")
+PLOTLY_DIR = os.environ.get("PLOTLY_DIR",
+                            os.path.join(os.path.expanduser("~"), ".plotly"))
+
 CREDENTIALS_FILE = os.path.join(PLOTLY_DIR, ".credentials")
 CONFIG_FILE = os.path.join(PLOTLY_DIR, ".config")
-TEST_DIR = os.path.join(os.path.expanduser("~"), ".test")
 TEST_FILE = os.path.join(PLOTLY_DIR, ".permission_test")
 
 # this sets both the DEFAULTS and the TYPES for these files
@@ -25,8 +26,6 @@
 
 def _permissions():
     try:
-        os.mkdir(TEST_DIR)
-        os.rmdir(TEST_DIR)
         if not os.path.exists(PLOTLY_DIR):
             os.mkdir(PLOTLY_DIR)
         with open(TEST_FILE, 'w') as f:
@@ -37,8 +36,12 @@ def _permissions():
         return False
 
 
-_file_permissions = _permissions()
+_file_permissions = None
 
 
-def check_file_permissions():
+def ensure_writable_plotly_dir():
+    # Cache permissions status
+    global _file_permissions
+    if _file_permissions is None:
+        _file_permissions = _permissions()
     return _file_permissions

Diff for: plotly/io/_orca.py

@@ -13,7 +13,7 @@
 from six import string_types
 
 import plotly
-from plotly.files import PLOTLY_DIR
+from plotly.files import PLOTLY_DIR, ensure_writable_plotly_dir
 from plotly.io._utils import validate_coerce_fig_to_dict
 from plotly.optional_imports import get_module
 
@@ -354,8 +354,13 @@ def save(self):
         -------
         None
         """
-        with open(self.config_file, 'w') as f:
-            json.dump(self._props, f, indent=4)
+        if ensure_writable_plotly_dir():
+            with open(self.config_file, 'w') as f:
+                json.dump(self._props, f, indent=4)
+        else:
+            warnings.warn("""\
+Failed to write orca configuration file at '{path}'""".format(
+                path=self.config_file))
 
     @property
     def port(self):

Diff for: plotly/plotly/plotly.py

@@ -57,9 +57,6 @@
     "'secret'."
 )
 
-# test file permissions and make sure nothing is corrupted
-tools.ensure_local_plotly_files()
-
 
 # don't break backwards compatibility
 def sign_in(username, api_key, **kwargs):

Diff for: plotly/tests/test_plot_ly/test_get_figure/test_get_figure.py

@@ -98,7 +98,7 @@ def test_get_figure_raw(self):
         py.get_figure('PlotlyImageTest', str(file_id), raw=True)
 
 
-class TestBytesVStrings(TestCase):
+class TestBytesVStrings(PlotlyTestCase):
 
     @skipIf(not six.PY3, 'Decoding and missing escapes only seen in PY3')
     def test_proper_escaping(self):

Diff for: plotly/tests/utils.py

@@ -36,16 +36,14 @@ def tearDown(self):
         self.restore_session()
 
     def stash_files(self):
-        if files.check_file_permissions():
-            self._credentials = utils.load_json_dict(files.CREDENTIALS_FILE)
-            self._config = utils.load_json_dict(files.CONFIG_FILE)
+        self._credentials = utils.load_json_dict(files.CREDENTIALS_FILE)
+        self._config = utils.load_json_dict(files.CONFIG_FILE)
 
     def restore_files(self):
-        if files.check_file_permissions():
-            if self._credentials is not None:
-                utils.save_json_dict(files.CREDENTIALS_FILE, self._credentials)
-            if self._config is not None:
-                utils.save_json_dict(files.CONFIG_FILE, self._config)
+        if self._credentials and files.ensure_writable_plotly_dir():
+            utils.save_json_dict(files.CREDENTIALS_FILE, self._credentials)
+        if self._config and files.ensure_writable_plotly_dir():
+            utils.save_json_dict(files.CONFIG_FILE, self._config)
 
     def stash_session(self):
         self._session = copy.deepcopy(session._session)

Diff for: plotly/tools.py

@@ -12,10 +12,11 @@
 import warnings
 
 import six
+import copy
 
 from plotly import exceptions, optional_imports, session, utils
 from plotly.files import (CONFIG_FILE, CREDENTIALS_FILE, FILE_CONTENT,
-                          check_file_permissions)
+                          ensure_writable_plotly_dir)
 
 DEFAULT_PLOTLY_COLORS = ['rgb(31, 119, 180)', 'rgb(255, 127, 14)',
                          'rgb(44, 160, 44)', 'rgb(214, 39, 40)',
@@ -78,7 +79,7 @@ def ensure_local_plotly_files():
     If the config or credential files aren't filled out, then write them
     to the disk.
     """
-    if check_file_permissions():
+    if ensure_writable_plotly_dir():
         for fn in [CREDENTIALS_FILE, CONFIG_FILE]:
             utils.ensure_file_exists(fn)
             contents = utils.load_json_dict(fn)
@@ -124,7 +125,7 @@ def set_credentials_file(username=None,
     :param (str) proxy_password: The pw associated with your Proxy un
 
     """
-    if not check_file_permissions():
+    if not ensure_writable_plotly_dir():
         raise exceptions.PlotlyError("You don't have proper file permissions "
                                      "to run this function.")
     ensure_local_plotly_files()  # make sure what's there is OK
@@ -152,11 +153,13 @@ def get_credentials_file(*args):
         get_credentials_file('username')
 
     """
-    if check_file_permissions():
-        ensure_local_plotly_files()  # make sure what's there is OK
-        return utils.load_json_dict(CREDENTIALS_FILE, *args)
-    else:
-        return FILE_CONTENT[CREDENTIALS_FILE]
+    # Read credentials from file if possible
+    credentials = utils.load_json_dict(CREDENTIALS_FILE, *args)
+    if not credentials:
+        # Credentials could not be read, use defaults
+        credentials = copy.copy(FILE_CONTENT[CREDENTIALS_FILE])
+
+    return credentials
 
 
 def reset_credentials_file():
@@ -185,7 +188,7 @@ def set_config_file(plotly_domain=None,
     :param (bool) world_readable: True = public, False = private
 
     """
-    if not check_file_permissions():
+    if not ensure_writable_plotly_dir():
         raise exceptions.PlotlyError("You don't have proper file permissions "
                                      "to run this function.")
     ensure_local_plotly_files()  # make sure what's there is OK
@@ -247,11 +250,13 @@ def get_config_file(*args):
         get_config_file('plotly_domain')
 
     """
-    if check_file_permissions():
-        ensure_local_plotly_files()  # make sure what's there is OK
-        return utils.load_json_dict(CONFIG_FILE, *args)
-    else:
-        return FILE_CONTENT[CONFIG_FILE]
+    # Read config from file if possible
+    config = utils.load_json_dict(CONFIG_FILE, *args)
+    if not config:
+        # Config could not be read, use defaults
+        config = copy.copy(FILE_CONTENT[CONFIG_FILE])
+
+    return config
 
 
 def reset_config_file():