Add plotly-cloud as optional dependency and mock the cli if not installed

Author: T4rk1n

dash/_plotly_cli.py

@@ -0,0 +1,15 @@
+import sys
+
+
+def cli():
+    try:
+        from plotly_cloud.cli import main  # pylint: disable=import-outside-toplevel
+
+        main()
+    except ImportError:
+        print(
+            "Plotly cloud is not installed,"
+            " install it with `pip install dash[cloud]` to use the plotly command",
+            file=sys.stderr,
+        )
+        sys.exit(-1)

setup.py

@@ -35,14 +35,16 @@ def read_req_file(req_type):
         "testing": read_req_file("testing"),
         "celery": read_req_file("celery"),
         "diskcache": read_req_file("diskcache"),
-        "compress": read_req_file("compress")
+        "compress": read_req_file("compress"),
+        "cloud": read_req_file("cloud"),
     },
     entry_points={
         "console_scripts": [
             "dash-generate-components = "
             "dash.development.component_generator:cli",
             "renderer = dash.development.build_process:renderer",
             "dash-update-components = dash.development.update_components:cli"
+            "plotly = dash._plotly_cli:cli"
         ],
         "pytest11": ["dash = dash.testing.plugin"],
     },