def _iter_interpreters():
# type: () -> Iterator[InterpreterOrError]
seen = set()
normalized_paths = (OrderedSet(
PythonInterpreter.canonicalize_path(p)
for p in path.split(os.pathsep)) if path else None)
# Prefer the current interpreter, if valid.
current_interpreter = preferred_interpreter or PythonInterpreter.get()
if not _valid_path or _valid_path(current_interpreter.binary):
if normalized_paths:
candidate_paths = frozenset(
(current_interpreter.binary,
os.path.dirname(current_interpreter.binary)))
candidate_paths_in_path = candidate_paths.intersection(
normalized_paths)
if candidate_paths_in_path:
# In case the full path of the current interpreter binary was in the
# `normalized_paths` we're searching, remove it to prevent identifying it again
# just to then skip it as `seen`.
normalized_paths.discard(current_interpreter.binary)
seen.add(current_interpreter)
yield current_interpreter
else:
seen.add(current_interpreter)
yield current_interpreter
for interp in PythonInterpreter.iter_candidates(
paths=normalized_paths, path_filter=_valid_path):
if interp not in seen:
seen.add(interp)
yield interp
def create_message(self, preamble=None):
# type: (Optional[str]) -> str
"""Create a message describing failure to find matching interpreters with an optional
preamble.
:param preamble: An optional preamble to the message that will be displayed above it
separated by an empty blank line.
:return: A descriptive message useable for display to an end user.
"""
preamble = "{}\n\n".format(preamble) if preamble else ""
failures_message = ""
if self.failures:
seen = set()
broken_interpreters = []
for python, error in self.failures:
canonical_python = PythonInterpreter.canonicalize_path(python)
if canonical_python not in seen:
broken_interpreters.append((canonical_python, error))
seen.add(canonical_python)
failures_message = (
"{}\n"
"\n"
"(See https://github.com/pantsbuild/pex/issues/1027 for a list of known breaks and "
"workarounds.)").format("\n".join(
"{index}.) {binary}:\n{error}".format(
index=i, binary=python, error=error)
for i, (python,
error) in enumerate(broken_interpreters, start=1)))
if not self.candidates:
if failures_message:
return (
"{preamble}"
"Interpreters were found but they all appear to be broken:\n"
"{failures}").format(preamble=preamble,
failures=failures_message)
return "{}No interpreters could be found on the system.".format(
preamble)
binary_column_width = max(
len(candidate.binary) for candidate in self.candidates)
interpreters_format = "{{index}}.) {{binary: >{}}} {{requirement}}".format(
binary_column_width)
qualifier = ""
if failures_message:
failures_message = "Skipped the following broken interpreters:\n{}".format(
failures_message)
qualifier = "working "
constraints_message = ""
if self.constraints:
constraints_message = (
"No {qualifier}interpreter compatible with the requested constraints was found:\n"
" {constraints}").format(qualifier=qualifier,
constraints="\n ".join(
self.constraints))
problems = "\n\n".join(msg for msg in (failures_message,
constraints_message) if msg)
if problems:
problems = "\n\n{}".format(problems)
return (
"{preamble}"
"Examined the following {qualifier}interpreters:\n"
"{interpreters}"
"{problems}").format(
preamble=preamble,
qualifier=qualifier,
interpreters="\n".join(
interpreters_format.format(
index=i,
binary=candidate.binary,
requirement=candidate.identity.requirement)
for i, candidate in enumerate(self.candidates, start=1)),
problems=problems,
)
