Split out utils into multiple files, add reraising support

gym/utils/__init__.py

@@ -0,0 +1,10 @@
+"""A set of common utilities used within the environments. These are
+not intended as API functions, and will not remain stable over time.
+"""
+
+# These submodules should not have any import-time dependencies.
+# We want this since we use `utils` during our import-time sanity checks
+# that verify that our dependencies are actually present.
+from .colorize import colorize
+from .ezpickle import EzPickle
+from .reraise import reraise

gym/utils/colorize.py

@@ -0,0 +1,35 @@
+"""A set of common utilities used within the environments. These are
+not intended as API functions, and will not remain stable over time.
+"""
+
+color2num = dict(
+    gray=30,
+    red=31,
+    green=32,
+    yellow=33,
+    blue=34,
+    magenta=35,
+    cyan=36,
+    white=37,
+    crimson=38
+)
+
+
+def colorize(string, color, bold=False, highlight = False):
+    """Return string surrounded by appropriate terminal color codes to
+    print colorized text.  Valid colors: gray, red, green, yellow,
+    blue, magenta, cyan, white, crimson
+    """
+
+    # Import six here so that `utils` has no import-time dependencies.
+    # We want this since we use `utils` during our import-time sanity checks
+    # that verify that our dependencies (including six) are actually present.
+    import six
+
+    attr = []
+    num = color2num[color]
+    if highlight: num += 10
+    attr.append(six.u(str(num)))
+    if bold: attr.append(six.u('1'))
+    attrs = six.u(';').join(attr)
+    return six.u('\x1b[%sm%s\x1b[0m') % (attrs, string)

gym/utils/ezpickle.py

@@ -1,35 +1,3 @@
-"""A set of common utilities used within the environments. These are
-not intended as API functions, and will not remain stable over time.
-"""
-
-import six
-
-color2num = dict(
-    gray=30,
-    red=31,
-    green=32,
-    yellow=33,
-    blue=34,
-    magenta=35,
-    cyan=36,
-    white=37,
-    crimson=38
-)
-
-
-def colorize(string, color, bold=False, highlight = False):
-    """Return string surrounded by appropriate terminal color codes to
-    print colorized text.  Valid colors: gray, red, green, yellow,
-    blue, magenta, cyan, white, crimson
-    """
-    attr = []
-    num = color2num[color]
-    if highlight: num += 10
-    attr.append(six.u(str(num)))
-    if bold: attr.append(six.u('1'))
-    attrs = six.u(';').join(attr)
-    return six.u('\x1b[%sm%s\x1b[0m') % (attrs, string)
-
 class EzPickle(object):
     """Objects that are pickled and unpickled via their constructor
     arguments.

gym/utils/reraise.py

@@ -0,0 +1,33 @@
+import sys
+
+# We keep the actual reraising in different modules since the
+# Python 2 version SyntaxError's in Python 3.
+if sys.version_info[0] < 3:
+    from .reraise_impl_py2 import reraise_impl
+else:
+    from .reraise_impl_py3 import reraise_impl
+
+def reraise(prefix=None, suffix=None):
+    old_exc_type, old_exc_value, traceback = sys.exc_info()
+    if old_exc_value is None:
+        old_exc_value = old_exc_type()
+    e = ReraisedException(old_exc_type, old_exc_value, prefix, suffix)
+
+    reraise_impl(e, traceback)
+
+class ReraisedException(Exception):
+    def __init__(self, old_exc_type, old_exc_value, prefix, suffix):
+        self.old_exc_type = old_exc_type
+        self.old_exc_value = old_exc_value
+        self.prefix = prefix
+        self.suffix = suffix
+
+    def __str__(self):
+        klass = self.old_exc_type
+        orig = "%s.%s: %s" % (klass.__module__, klass.__name__, klass.__str__(self.old_exc_value))
+        prefixpart = suffixpart = ''
+        if self.prefix != '':
+            prefixpart = self.prefix + "\n"
+        if self.suffix != '':
+            suffixpart = "\n\n" + self.suffix
+        return "%sThe original exception was:\n\n%s%s" % (prefixpart, orig, suffixpart)

gym/utils/reraise_impl_py2.py

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+def reraise_impl(e, traceback):
+    raise e.__class__, e, traceback

gym/utils/reraise_impl_py3.py

@@ -0,0 +1,2 @@
+def reraise_impl(e, traceback):
+    raise e.with_traceback(traceback)