1 files changed, 104 insertions, 0 deletions
diff --git a/waflib/extras/run_py_script.py b/waflib/extras/run_py_script.py
new file mode 100644
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+++ b/waflib/extras/run_py_script.py
@@ -0,0 +1,104 @@
+#!/usr/bin/env python
+# encoding: utf-8
+# Hans-Martin von Gaudecker, 2012
+
+"""
+Run a Python script in the directory specified by **ctx.bldnode**.
+
+Select a Python version by specifying the **version** keyword for
+the task generator instance as integer 2 or 3. Default is 3.
+
+If the build environment has an attribute "PROJECT_PATHS" with
+a key "PROJECT_ROOT", its value will be appended to the PYTHONPATH.
+Same a string passed to the optional **add_to_pythonpath**
+keyword (appended after the PROJECT_ROOT).
+
+Usage::
+
+    ctx(features='run_py_script', version=3,
+        source='some_script.py',
+        target=['some_table.tex', 'some_figure.eps'],
+        deps='some_data.csv',
+        add_to_pythonpath='src/some/library')
+"""
+
+import os, re
+from waflib import Task, TaskGen, Logs
+
+
+def configure(conf):
+	"""TODO: Might need to be updated for Windows once
+	"PEP 397":http://www.python.org/dev/peps/pep-0397/ is settled.
+	"""
+	conf.find_program('python', var='PY2CMD', mandatory=False)
+	conf.find_program('python3', var='PY3CMD', mandatory=False)
+	if not conf.env.PY2CMD and not conf.env.PY3CMD:
+		conf.fatal("No Python interpreter found!")
+
+class run_py_2_script(Task.Task):
+	"""Run a Python 2 script."""
+	run_str = '${PY2CMD} ${SRC[0].abspath()}'
+	shell=True
+
+class run_py_3_script(Task.Task):
+	"""Run a Python 3 script."""
+	run_str = '${PY3CMD} ${SRC[0].abspath()}'
+	shell=True
+
+@TaskGen.feature('run_py_script')
+@TaskGen.before_method('process_source')
+def apply_run_py_script(tg):
+	"""Task generator for running either Python 2 or Python 3 on a single
+	script.
+
+	Attributes:
+
+		* source -- A **single** source node or string. (required)
+		* target -- A single target or list of targets (nodes or strings)
+		* deps -- A single dependency or list of dependencies (nodes or strings)
+		* add_to_pythonpath -- A string that will be appended to the PYTHONPATH environment variable
+
+	If the build environment has an attribute "PROJECT_PATHS" with
+	a key "PROJECT_ROOT", its value will be appended to the PYTHONPATH.
+	"""
+
+	# Set the Python version to use, default to 3.
+	v = getattr(tg, 'version', 3)
+	if v not in (2, 3):
+		raise ValueError("Specify the 'version' attribute for run_py_script task generator as integer 2 or 3.\n Got: %s" %v)
+
+	# Convert sources and targets to nodes
+	src_node = tg.path.find_resource(tg.source)
+	tgt_nodes = [tg.path.find_or_declare(t) for t in tg.to_list(tg.target)]
+
+	# Create the task.
+	tsk = tg.create_task('run_py_%d_script' %v, src=src_node, tgt=tgt_nodes)
+
+	# custom execution environment
+	# TODO use a list and  os.sep.join(lst) at the end instead of concatenating strings
+	tsk.env.env = dict(os.environ)
+	tsk.env.env['PYTHONPATH'] = tsk.env.env.get('PYTHONPATH', '')
+	project_paths = getattr(tsk.env, 'PROJECT_PATHS', None)
+	if project_paths and 'PROJECT_ROOT' in project_paths:
+		tsk.env.env['PYTHONPATH'] += os.pathsep + project_paths['PROJECT_ROOT'].abspath()
+	if getattr(tg, 'add_to_pythonpath', None):
+		tsk.env.env['PYTHONPATH'] += os.pathsep + tg.add_to_pythonpath
+
+	# Clean up the PYTHONPATH -- replace double occurrences of path separator
+	tsk.env.env['PYTHONPATH'] = re.sub(os.pathsep + '+', os.pathsep, tsk.env.env['PYTHONPATH'])
+
+	# Clean up the PYTHONPATH -- doesn't like starting with path separator
+	if tsk.env.env['PYTHONPATH'].startswith(os.pathsep):
+		 tsk.env.env['PYTHONPATH'] = tsk.env.env['PYTHONPATH'][1:]
+
+	# dependencies (if the attribute 'deps' changes, trigger a recompilation)
+	for x in tg.to_list(getattr(tg, 'deps', [])):
+		node = tg.path.find_resource(x)
+		if not node:
+			tg.bld.fatal('Could not find dependency %r for running %r' % (x, src_node.abspath()))
+		tsk.dep_nodes.append(node)
+	Logs.debug('deps: found dependencies %r for running %r', tsk.dep_nodes, src_node.abspath())
+
+	# Bypass the execution of process_source by setting the source to an empty list
+	tg.source = []
+