Fix scripts to run w/o .pudl.yml, create user environment.yml

Fixed try/except logic in setup module to catch FileNotFoundError
correctly, and return None for pudl_in and pudl_out if there's no
default file supplied by the user.

Closes #406

Also created a separate "user" environment.yml file that is stored in
`package_data` and deployed by the `pudl_setup` script, which installed
catalystcoop.pudl using conda... or at least, it will, when the package
is available on conda-forge.  Will still need to figure out what the
right way is to bootstrap the user into that conda environment, but
that's a documentation issue.  Will also obviously need to test the
environment.yml file deployed in a clean environment.

Progress toward #383

environment.yml

@@ -1,4 +1,4 @@
-name: pudl
+name: pudl-dev
 channels:
   - conda-forge
   - defaults
@@ -21,7 +21,7 @@ dependencies:
   - jedi                # dev
   - jupyter             # user
   - jupyterlab          # user
-  - matplotlib          # user
+  - matplotlib          # base
   - nbval               # dev
   - networkx>=2.2       # base We depend on features introduced in v2.2
   - numpy               # base

src/pudl/package_data/environment.yml

@@ -0,0 +1,11 @@
+name: pudl
+channels:
+  - conda-forge
+  - defaults
+dependencies:
+  - catalystcoop.pudl
+  - dask
+  - jupyter
+  - jupyterlab
+  - pip
+  - python>=3.7

src/pudl/workspace/setup.py

@@ -63,13 +63,13 @@ def get_defaults():
     """
     settings_file = pathlib.Path.home() / '.pudl.yml'
 
-    with pathlib.Path(settings_file).open() as f:
-        try:
+    try:
+        with pathlib.Path(settings_file).open() as f:
             default_workspace = yaml.safe_load(f)
-        except FileNotFoundError:
-            logger.warning("PUDL user settings file .pudl.yml not found.")
-            default_workspace = {"pudl_in": None, "pudl_out": None}
-            return default_workspace
+    except FileNotFoundError:
+        logger.warning("PUDL user settings file .pudl.yml not found.")
+        default_workspace = {"pudl_in": None, "pudl_out": None}
+        return default_workspace
 
     # Ensure that no matter what the user has put in this file, we get fully
     # specified absolute paths out when we read it:
@@ -189,6 +189,10 @@ def init(pudl_in, pudl_out, clobber=False):
     notebook_pkg = "pudl.package_data.notebooks"
     deploy(notebook_pkg, notebook_dir, ignore_files, clobber=clobber)
 
+    # Deploy the pudl user environment file.
+    environment_pkg = "pudl.package_data"
+    deploy(environment_pkg, ps["pudl_out"], ignore_files, clobber=clobber)
+
 
 def deploy(pkg_path, deploy_dir, ignore_files, clobber=False):
     """

tox.ini

@@ -131,7 +131,7 @@ commands =
     {[testenv:linters]commands}
     {[testenv:docs]commands}
     {[testenv:etl]commands}
-    pudl_setup
+    pudl_setup --help
     pudl_data --help
     ferc1_to_sqlite --help
     pudl_etl --help