don't raise exception when one of the registered processes cannot be …

…imported (#226)

CHANGELOG.rst

@@ -5,6 +5,7 @@ Changelog
 ----
 0.31
 ----
+* don't raise exception when one of the registered processes cannot be imported (#225)
 * don't close pool between zoom levels (#227)
 
 ----

mapchete/cli/default/processes.py

@@ -2,9 +2,9 @@
 
 import click
 import logging
-import pkg_resources
 
 from mapchete.cli import utils
+from mapchete.processes import process_names_docstrings
 
 logger = logging.getLogger(__name__)
 
@@ -13,38 +13,19 @@
 @click.option(
     "--process_name", "-n", type=click.STRING, help="Print docstring of process."
 )
-@click.option(
-    "--docstrings", is_flag=True, help="Print docstrings of all processes."
-)
 @utils.opt_debug
 def processes(process_name=None, docstrings=False, debug=False):
     """List available processes."""
-    # get all registered processes
-    processes = list(pkg_resources.iter_entry_points("mapchete.processes"))
-
-    # print selected process
-    if process_name:
-        for v in processes:
-            logger.debug("try to load %s", v)
-            process_module = v.load()
-            if process_name == process_module.__name__:
-                _print_process_info(process_module, docstrings=True)
-    else:
-        # print all processes
-        click.echo("%s processes found" % len(processes))
-        loaded_processes = [v.load() for v in processes]
-        loaded_processes.sort(key=lambda x: x.__name__)
-        for process_module in loaded_processes:
-            _print_process_info(process_module, docstrings=docstrings)
-
-
-def _print_process_info(process_module, docstrings=False):
-    click.echo(
-        click.style(
-            process_module.__name__,
-            bold=docstrings,
-            underline=docstrings
-        )
-    )
-    if docstrings:
-        click.echo(process_module.execute.__doc__)
+    processes = process_names_docstrings(process_name=process_name)
+    click.echo("%s processes found" % len(processes))
+    for process_info in processes:
+        _print_process_info(process_info, print_docstring=process_name is not None)
+
+
+def _print_process_info(process_info, print_docstring=False):
+    name, docstring = process_info
+    # print process name
+    click.echo(click.style(name, bold=print_docstring, underline=print_docstring))
+    # print process docstring
+    if print_docstring:
+        click.echo(docstring)

mapchete/processes/__init__.py

@@ -0,0 +1,57 @@
+import logging
+import pkg_resources
+
+logger = logging.getLogger(__name__)
+
+
+def registered_processes(process_name=None):
+    """
+    Return registered process modules.
+
+    Parameters
+    ----------
+    process_name : str
+        Python path of process.
+
+    Returns
+    -------
+    module
+    """
+    def _import():
+        # get all registered processes by name
+        processes = list(pkg_resources.iter_entry_points("mapchete.processes"))
+        # try to load processes
+        for v in processes:
+            logger.debug("try to load %s", v)
+            try:
+                loaded = v.load()
+                if process_name is None or process_name == loaded.__name__:
+                    yield loaded
+            except Exception as e:
+                logger.warning("%s could not be imported: %s", str(v), str(e))
+
+    # sort processes alphabetically
+    imported = list(_import())
+    imported.sort(key=lambda x: x.__name__)
+    logger.debug("%s processes found", len(imported))
+    return imported
+
+
+def process_names_docstrings(process_name):
+    """
+    Return registered process module names and docstrings.
+
+    Parameters
+    ----------
+    process_name : str
+        Python path of process
+
+    Returns
+    -------
+    list of tuples
+        tuples contain containing process name and process docstring
+    """
+    return [
+        (process.__name__, process.execute.__doc__)
+        for process in registered_processes(process_name=process_name)
+    ]