From b03e79886e22d4b0a258e93ab1445743107d391d Mon Sep 17 00:00:00 2001
From: David Euresti <github@euresti.com>
Date: Tue, 4 Apr 2017 00:21:35 -0400
Subject: [PATCH] Fix os.getenv and friends to have consistent types (#1131)

---
 stdlib/2/os/__init__.pyi | 34 ++++++++++++++++++++++------------
 stdlib/3/os/__init__.pyi | 20 +++++++++++++-------
 2 files changed, 35 insertions(+), 19 deletions(-)

diff --git a/stdlib/2/os/__init__.pyi b/stdlib/2/os/__init__.pyi
index c11d9728f..881bcf73f 100644
--- a/stdlib/2/os/__init__.pyi
+++ b/stdlib/2/os/__init__.pyi
@@ -1,13 +1,16 @@
 # created from https://docs.python.org/2/library/os.html
 
+from builtins import OSError as error
+import sys
 from typing import (
     Mapping, MutableMapping, Dict, List, Any, Tuple, Iterator, overload, Union, AnyStr,
-    Optional, Generic, Set, Callable, Text, Sequence, IO, NamedTuple
+    Optional, Generic, Set, Callable, Text, Sequence, IO, NamedTuple, TypeVar
 )
-from . import path
+from . import path as path
 from mypy_extensions import NoReturn
 
-error = OSError
+_T = TypeVar('_T')
+
 SEEK_SET = 0
 SEEK_CUR = 0
 SEEK_END = 0
@@ -58,13 +61,15 @@ R_OK = 0
 W_OK = 0
 X_OK = 0
 
-class _Environ(MutableMapping[str, str]):
-    def copy(self) -> Dict[str, str]: ...
+class _Environ(MutableMapping[AnyStr, AnyStr], Generic[AnyStr]):
+    def copy(self) -> Dict[AnyStr, AnyStr]: ...
+
+environ = ...  # type: _Environ[str]
+
+confstr_names = ...  # type: Dict[str, int]  # Unix only
+pathconf_names = ...  # type: Dict[str, int]  # Unix only
+sysconf_names = ...  # type: Dict[str, int]  # Unix only
 
-environ = ...  # type: _Environ
-confstr_names = ...  # type: Mapping[str, int]  # Unix only
-pathconf_names = ...  # type: Mapping[str, int]  # Unix only
-sysconf_names = ...  # type: Mapping[str, int]  # Unix only
 EX_OK = 0        # Unix only
 EX_USAGE = 0     # Unix only
 EX_DATAERR = 0   # Unix only
@@ -112,8 +117,6 @@ def getppid() -> int: ...
 def getresuid() -> Tuple[int, int, int]: ...  # Unix only
 def getresgid() -> Tuple[int, int, int]: ...  # Unix only
 def getuid() -> int: ...  # Unix only
-def getenv(varname: unicode, value: unicode = ...) -> str: ...
-def putenv(varname: unicode, value: unicode) -> None: ...
 def setegid(egid: int) -> None: ...  # Unix only
 def seteuid(euid: int) -> None: ...  # Unix only
 def setgid(gid: int) -> None: ...  # Unix only
@@ -130,7 +133,14 @@ def setuid(uid: int) -> None: ...  # Unix only
 def strerror(code: int) -> str: ...
 def umask(mask: int) -> int: ...
 def uname() -> Tuple[str, str, str, str, str]: ...  # Unix only
-def unsetenv(varname: str) -> None: ...
+
+@overload
+def getenv(key: Text) -> Optional[str]: ...
+@overload
+def getenv(key: Text, default: _T) -> Union[str, _T]: ...
+def putenv(key: Union[bytes, Text], value: Union[bytes, Text]) -> None: ...
+def unsetenv(key: Union[bytes, Text]) -> None: ...
+
 def fdopen(fd: int, *args, **kwargs) -> IO[Any]: ...
 def close(fd: int) -> None: ...
 def closerange(fd_low: int, fd_high: int) -> None: ...
diff --git a/stdlib/3/os/__init__.pyi b/stdlib/3/os/__init__.pyi
index 2324a9343..c35cdcb55 100644
--- a/stdlib/3/os/__init__.pyi
+++ b/stdlib/3/os/__init__.pyi
@@ -8,11 +8,13 @@ from io import TextIOWrapper as _TextIOWrapper
 import sys
 from typing import (
     Mapping, MutableMapping, Dict, List, Any, Tuple, Iterator, overload, Union, AnyStr,
-    Optional, Generic, Set, Callable, Text, Sequence
+    Optional, Generic, Set, Callable, Text, Sequence, NamedTuple, TypeVar
 )
-from . import path
+from . import path as path
 from mypy_extensions import NoReturn
 
+_T = TypeVar('_T')
+
 # ----- os variables -----
 
 supports_bytes_environ = False  # TODO: True when bytes implemented?
@@ -236,10 +238,6 @@ def getppid() -> int: ...
 def getresuid() -> Tuple[int, int, int]: ...  # Unix only
 def getresgid() -> Tuple[int, int, int]: ...  # Unix only
 def getuid() -> int: ...  # Unix only
-def getenv(key: str, default: str = ...) -> str: ...
-def getenvb(key: bytes, default: bytes = ...) -> bytes: ...
-# TODO mixed str/bytes putenv arguments
-def putenv(key: AnyStr, value: AnyStr) -> None: ...
 def setegid(egid: int) -> None: ...  # Unix only
 def seteuid(euid: int) -> None: ...  # Unix only
 def setgid(gid: int) -> None: ...  # Unix only
@@ -256,7 +254,15 @@ def setuid(uid: int) -> None: ...  # Unix only
 def strerror(code: int) -> str: ...
 def umask(mask: int) -> int: ...
 def uname() -> Tuple[str, str, str, str, str]: ...  # Unix only
-def unsetenv(key: _PathType) -> None: ...
+
+@overload
+def getenv(key: Text) -> Optional[str]: ...
+@overload
+def getenv(key: Text, default: _T) -> Union[str, _T]: ...
+def getenvb(key: bytes, default: bytes = ...) -> bytes: ...
+def putenv(key: Union[bytes, Text], value: Union[bytes, Text]) -> None: ...
+def unsetenv(key: Union[bytes, Text]) -> None: ...
+
 # Return IO or TextIO
 def fdopen(fd: int, mode: str = ..., buffering: int = ..., encoding: str = ...,
            errors: str = ..., newline: str = ..., closefd: bool = ...) -> Any: ...