Fix some type errors in os module. (#1101)

* Fix some type errors in os module.

Found these because they were different between Python 2 and 3.

* Code Review changes

* Make it __arg0

stdlib/2/os/__init__.pyi

@@ -1,8 +1,8 @@
 # created from https://docs.python.org/2/library/os.html
 
 from typing import (
-    List, Tuple, Union, Sequence, Mapping, IO, Any, Optional, AnyStr, Iterator,
-    Dict, MutableMapping, NamedTuple, overload, Text
+    Mapping, MutableMapping, Dict, List, Any, Tuple, Iterator, overload, Union, AnyStr,
+    Optional, Generic, Set, Callable, Text, Sequence, IO, NamedTuple
 )
 from . import path
 from mypy_extensions import NoReturn
@@ -118,7 +118,7 @@ def setegid(egid: int) -> None: ...  # Unix only
 def seteuid(euid: int) -> None: ...  # Unix only
 def setgid(gid: int) -> None: ...  # Unix only
 def setgroups(groups: Sequence[int]) -> None: ...  # Unix only
-def setpgrp(*args) -> None: ...  # Unix only
+def setpgrp() -> None: ...  # Unix only
 def setpgid(pid: int, pgrp: int) -> None: ...  # Unix only
 def setregid(rgid: int, egid: int) -> None: ...  # Unix only
 def setresgid(rgid: int, egid: int, sgid: int) -> None: ...  # Unix only
@@ -126,7 +126,7 @@ def setresuid(ruid: int, euid: int, suid: int) -> None: ...  # Unix only
 def setreuid(ruid: int, euid: int) -> None: ...  # Unix only
 def getsid(pid: int) -> int: ...  # Unix only
 def setsid() -> None: ...  # Unix only
-def setuid(pid: int) -> None: ...  # Unix only
+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
@@ -139,21 +139,21 @@ def dup2(fd: int, fd2: int) -> None: ...
 def fchmod(fd: int, mode: int) -> None: ...  # Unix only
 def fchown(fd: int, uid: int, gid: int) -> None: ...  # Unix only
 def fdatasync(fd: int) -> None: ...  # Unix only, not Mac
-def fpathconf(fd: int, name: str) -> None: ...  # Unix only
+def fpathconf(fd: int, name: Union[str, int]) -> int: ...  # Unix only
 def fstat(fd: int) -> Any: ...
 def fstatvfs(fd: int) -> _StatVFS: ...  # Unix only
 def fsync(fd: int) -> None: ...
 def ftruncate(fd: int, length: int) -> None: ...  # Unix only
 def isatty(fd: int) -> bool: ...  # Unix only
-def lseek(fd: int, pos: int, how: int) -> None: ...
+def lseek(fd: int, pos: int, how: int) -> int: ...
 def open(file: _PathType, flags: int, mode: int = ...) -> int: ...
 def openpty() -> Tuple[int, int]: ...  # some flavors of Unix
 def pipe() -> Tuple[int, int]: ...
-def read(fd: int, n: int) -> str: ...
+def read(fd: int, n: int) -> bytes: ...
 def tcgetpgrp(fd: int) -> int: ...  # Unix only
 def tcsetpgrp(fd: int, pg: int) -> None: ...  # Unix only
 def ttyname(fd: int) -> str: ...  # Unix only
-def write(fd: int, str: str) -> int: ...
+def write(fd: int, string: bytes) -> int: ...
 def access(path: _PathType, mode: int) -> bool: ...
 def chdir(path: _PathType) -> None: ...
 def fchdir(fd: int) -> None: ...
@@ -164,9 +164,9 @@ def chroot(path: _PathType) -> None: ...  # Unix only
 def chmod(path: _PathType, mode: int) -> None: ...
 def chown(path: _PathType, uid: int, gid: int) -> None: ...  # Unix only
 def lchflags(path: _PathType, flags: int) -> None: ...  # Unix only
-def lchmod(path: _PathType, uid: int, gid: int) -> None: ...  # Unix only
+def lchmod(path: _PathType, mode: int) -> None: ...  # Unix only
 def lchown(path: _PathType, uid: int, gid: int) -> None: ...  # Unix only
-def link(source: _PathType, link_name: _PathType) -> None: ...
+def link(src: _PathType, link_name: _PathType) -> None: ...
 def listdir(path: AnyStr) -> List[AnyStr]: ...
 def lstat(path: _PathType) -> Any: ...
 def mkfifo(path: _PathType, mode: int = ...) -> None: ...  # Unix only
@@ -176,7 +176,7 @@ def minor(device: int) -> int: ...
 def makedev(major: int, minor: int) -> int: ...
 def mkdir(path: _PathType, mode: int = ...) -> None: ...
 def makedirs(path: _PathType, mode: int = ...) -> None: ...
-def pathconf(path: _PathType, name: str) -> str: ...  # Unix only
+def pathconf(path: _PathType, name: Union[str, int]) -> int: ...  # Unix only
 def readlink(path: AnyStr) -> AnyStr: ...
 def remove(path: _PathType) -> None: ...
 def removedirs(path: _PathType) -> None: ...
@@ -191,16 +191,21 @@ def stat_float_times() -> bool: ...
 def statvfs(path: _PathType) -> _StatVFS: ...  # Unix only
 def symlink(source: _PathType, link_name: _PathType) -> None: ...
 def unlink(path: _PathType) -> None: ...
-def utime(path: _PathType, times: Optional[Tuple[int, int]]) -> None: ...
+def utime(path: _PathType, times: Optional[Tuple[float, float]]) -> None: ...
+
+# TODO onerror: function from OSError to void
 def walk(top: AnyStr, topdown: bool = ..., onerror: Any = ...,
          followlinks: bool = ...) -> Iterator[Tuple[AnyStr, List[AnyStr],
                                                     List[AnyStr]]]: ...
 
-def abort() -> None: ...
-def execl(file: _PathType, *args) -> None: ...
-def execle(file: _PathType, *args) -> None: ...
-def execlp(file: _PathType, *args) -> None: ...
-def execlpe(file: _PathType, *args) -> None: ...
+def abort() -> NoReturn: ...
+# These are defined as execl(file, *args) but the first *arg is mandatory.
+def execl(file: _PathType, __arg0: Union[bytes, Text], *args: Union[bytes, Text]) -> NoReturn: ...
+def execlp(file: _PathType, __arg0: Union[bytes, Text], *args: Union[bytes, Text]) -> NoReturn: ...
+
+# These are: execle(file, *args, env) but env is pulled from the last element of the args.
+def execle(file: _PathType, __arg0: Union[bytes, Text], *args: Any) -> NoReturn: ...
+def execlpe(file: _PathType, __arg0: Union[bytes, Text], *args: Any) -> NoReturn: ...
 
 # The docs say `args: tuple or list of strings`
 # The implementation enforces tuple or list so we can't use Sequence.
@@ -254,7 +259,7 @@ def WTERMSIG(status: int) -> int: ...  # Unix only
 def confstr(name: Union[str, int]) -> Optional[str]: ...  # Unix only
 def getloadavg() -> Tuple[float, float, float]: ...  # Unix only
 def sysconf(name: Union[str, int]) -> int: ...  # Unix only
-def urandom(n: int) -> str: ...
+def urandom(n: int) -> bytes: ...
 
 def tmpfile() -> IO[Any]: ...
 def tmpnam() -> str: ...

stdlib/3/os/__init__.pyi

@@ -8,7 +8,7 @@ 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
+    Optional, Generic, Set, Callable, Text, Sequence
 )
 from . import path
 from mypy_extensions import NoReturn
@@ -243,15 +243,15 @@ 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
-def setgroups(groups: List[int]) -> None: ...  # Unix only
-def setpgrp() -> int: ...  # Unix only
-def setpgid(pid: int, pgrp: int) -> int: ...  # Unix only
+def setgroups(groups: Sequence[int]) -> None: ...  # Unix only
+def setpgrp() -> None: ...  # Unix only
+def setpgid(pid: int, pgrp: int) -> None: ...  # Unix only
 def setregid(rgid: int, egid: int) -> None: ...  # Unix only
 def setresgid(rgid: int, egid: int, sgid: int) -> None: ...  # Unix only
 def setresuid(ruid: int, euid: int, suid: int) -> None: ...  # Unix only
 def setreuid(ruid: int, euid: int) -> None: ...  # Unix only
 def getsid(pid: int) -> int: ...  # Unix only
-def setsid() -> int: ...  # Unix only
+def setsid() -> None: ...  # Unix only
 def setuid(uid: int) -> None: ...  # Unix only
 def strerror(code: int) -> str: ...
 def umask(mask: int) -> int: ...
@@ -268,7 +268,7 @@ def dup2(fd: int, fd2: int) -> None: ...
 def fchmod(fd: int, mode: int) -> None: ...  # Unix only
 def fchown(fd: int, uid: int, gid: int) -> None: ...  # Unix only
 def fdatasync(fd: int) -> None: ...  # Unix only, not Mac
-def fpathconf(fd: int, name: str) -> int: ...  # Unix only
+def fpathconf(fd: int, name: Union[str, int]) -> int: ...  # Unix only
 def fstat(fd: int) -> stat_result: ...
 def fstatvfs(fd: int) -> statvfs_result: ...  # Unix only
 def fsync(fd: int) -> None: ...
@@ -311,7 +311,7 @@ def makedev(major: int, minor: int) -> int: ...
 def mkdir(path: _PathType, mode: int = ...) -> None: ...
 def makedirs(path: _PathType, mode: int = ...,
              exist_ok: bool = ...) -> None: ...
-def pathconf(path: _PathType, name: str) -> int: ...  # Unix only
+def pathconf(path: _PathType, name: Union[str, int]) -> int: ...  # Unix only
 def readlink(path: AnyStr) -> AnyStr: ...
 def remove(path: _PathType) -> None: ...
 def removedirs(path: _PathType) -> None: ...
@@ -332,20 +332,21 @@ def symlink(source: _PathType, link_name: _PathType,
             target_is_directory: bool = ...) -> None:
     ...  # final argument in Windows only
 def unlink(path: _PathType) -> None: ...
-def utime(path: _PathType, times: Union[Tuple[int, int], Tuple[float, float]] = ...) -> None: ...
+def utime(path: _PathType, times: Optional[Tuple[float, float]] = ...) -> None: ...
 
 # TODO onerror: function from OSError to void
 def walk(top: AnyStr, topdown: bool = ..., onerror: Any = ...,
          followlinks: bool = ...) -> Iterator[Tuple[AnyStr, List[AnyStr],
                                                     List[AnyStr]]]: ...
 
-def abort() -> 'None': ...
-def execl(path: _PathType, arg0: Union[bytes, Text], *args: Union[bytes, Text]) -> None: ...
-def execle(path: _PathType, arg0: Union[bytes, Text],
-           *args: Any) -> None: ...  # Imprecise signature
-def execlp(path: _PathType, arg0: Union[bytes, Text], *args: Union[bytes, Text]) -> None: ...
-def execlpe(path: _PathType, arg0: Union[bytes, Text],
-            *args: Any) -> None: ...  # Imprecise signature
+def abort() -> NoReturn: ...
+# These are defined as execl(file, *args) but the first *arg is mandatory.
+def execl(file: _PathType, __arg0: Union[bytes, Text], *args: Union[bytes, Text]) -> NoReturn: ...
+def execlp(file: _PathType, __arg0: Union[bytes, Text], *args: Union[bytes, Text]) -> NoReturn: ...
+
+# These are: execle(file, *args, env) but env is pulled from the last element of the args.
+def execle(file: _PathType, __arg0: Union[bytes, Text], *args: Any) -> NoReturn: ...
+def execlpe(file: _PathType, __arg0: Union[bytes, Text], *args: Any) -> NoReturn: ...
 
 # The docs say `args: tuple or list of strings`
 # The implementation enforces tuple or list so we can't use Sequence.
@@ -388,19 +389,19 @@ def system(command: _PathType) -> int: ...
 def times() -> Tuple[float, float, float, float, float]: ...
 def wait() -> Tuple[int, int]: ...  # Unix only
 def waitpid(pid: int, options: int) -> Tuple[int, int]: ...
-def wait3(options: Union[int, None] = ...) -> Tuple[int, int, Any]: ...  # Unix only
+def wait3(options: int) -> Tuple[int, int, Any]: ...  # Unix only
 def wait4(pid: int, options: int) -> Tuple[int, int, Any]: ...  # Unix only
 def WCOREDUMP(status: int) -> bool: ...  # Unix only
 def WIFCONTINUED(status: int) -> bool: ...  # Unix only
 def WIFSTOPPED(status: int) -> bool: ...  # Unix only
 def WIFSIGNALED(status: int) -> bool: ...  # Unix only
 def WIFEXITED(status: int) -> bool: ...  # Unix only
-def WEXITSTATUS(status: int) -> bool: ...  # Unix only
-def WSTOPSIG(status: int) -> bool: ...  # Unix only
-def WTERMSIG(status: int) -> bool: ...  # Unix only
-def confstr(name: str) -> str: ...  # Unix only
+def WEXITSTATUS(status: int) -> int: ...  # Unix only
+def WSTOPSIG(status: int) -> int: ...  # Unix only
+def WTERMSIG(status: int) -> int: ...  # Unix only
+def confstr(name: Union[str, int]) -> Optional[str]: ...  # Unix only
 def getloadavg() -> Tuple[float, float, float]: ...  # Unix only
-def sysconf(name: str) -> int: ...  # Unix only
+def sysconf(name: Union[str, int]) -> int: ...  # Unix only
 def urandom(n: int) -> bytes: ...
 
 def sched_getaffinity(id: int) -> Set[int]: ...