Change empty string literals to ellipsis (#377)

For pytype compatibility

stdlib/2.7/Cookie.pyi

@@ -14,7 +14,7 @@ class Morsel(dict):
     value = ... # type: Any
     coded_value = ... # type: Any
     def set(self, key, val, coded_val, LegalChars=..., idmap=..., translate=...): ...
-    def output(self, attrs=None, header=''): ...
+    def output(self, attrs=None, header=...): ...
     def js_output(self, attrs=None): ...
     def OutputString(self, attrs=None): ...
 
@@ -23,7 +23,7 @@ class BaseCookie(dict):
     def value_encode(self, val): ...
     def __init__(self, input=None): ...
     def __setitem__(self, key, value): ...
-    def output(self, attrs=None, header='', sep=''): ...
+    def output(self, attrs=None, header=..., sep=...): ...
     def js_output(self, attrs=None): ...
     def load(self, rawdata): ...
 

stdlib/2.7/calendar.pyi

@@ -51,7 +51,7 @@ class HTMLCalendar(Calendar):
     def formatmonthname(self, theyear: int, themonth: int, withyear: bool = ...) -> str: ...
     def formatmonth(self, theyear: int, themonth: int, withyear: bool = ...) -> str: ...
     def formatyear(self, theyear: int, width: int = 3) -> str: ...
-    def formatyearpage(self, theyear: int, width: int = 3, css: Optional[str] = 'calendar.css', encoding: Optional[str] = ...) -> str: ...
+    def formatyearpage(self, theyear: int, width: int = 3, css: Optional[str] = ..., encoding: Optional[str] = ...) -> str: ...
 
 class TimeEncoding:
     def __init__(self, locale: LocaleType) -> None: ...

stdlib/2.7/email/utils.pyi

@@ -1,6 +1,6 @@
 # Stubs for email.utils (Python 2)
 #
-# NOTE: This dynamically typed stub was automatically generated by stubgen.
+# Derived from stub automatically generated by stubgen.
 
 from email._parseaddr import AddressList as _AddressList
 from email._parseaddr import mktime_tz as mktime_tz
@@ -19,4 +19,4 @@ def unquote(str): ...
 def decode_rfc2231(s): ...
 def encode_rfc2231(s, charset=None, language=None): ...
 def decode_params(params): ...
-def collapse_rfc2231_value(value, errors='', fallback_charset=''): ...
+def collapse_rfc2231_value(value, errors=..., fallback_charset=...): ...

stdlib/2.7/platform.pyi

@@ -1,33 +1,33 @@
 # Stubs for platform (Python 2)
 #
-# NOTE: This dynamically typed stub was automatically generated by stubgen.
+# Based on stub generated by stubgen.
 
 from typing import Any
 
 __copyright__ = ... # type: Any
 DEV_NULL = ... # type: Any
 
-def libc_ver(executable=..., lib='', version='', chunksize=2048): ...
-def linux_distribution(distname='', version='', id='', supported_dists=..., full_distribution_name=1): ...
-def dist(distname='', version='', id='', supported_dists=...): ...
+def libc_ver(executable=..., lib=..., version=..., chunksize=2048): ...
+def linux_distribution(distname=..., version=..., id=..., supported_dists=..., full_distribution_name=1): ...
+def dist(distname=..., version=..., id=..., supported_dists=...): ...
 
 class _popen:
     tmpfile = ... # type: Any
     pipe = ... # type: Any
     bufsize = ... # type: Any
     mode = ... # type: Any
-    def __init__(self, cmd, mode='', bufsize=None): ...
+    def __init__(self, cmd, mode=..., bufsize=None): ...
     def read(self): ...
     def readlines(self): ...
     def close(self, remove=..., error=...): ...
     __del__ = ... # type: Any
 
-def popen(cmd, mode='', bufsize=None): ...
-def win32_ver(release='', version='', csd='', ptype=''): ...
-def mac_ver(release='', versioninfo=..., machine=''): ...
-def java_ver(release='', vendor='', vminfo=..., osinfo=...): ...
+def popen(cmd, mode=..., bufsize=None): ...
+def win32_ver(release=..., version=..., csd=..., ptype=...): ...
+def mac_ver(release=..., versioninfo=..., machine=...): ...
+def java_ver(release=..., vendor=..., vminfo=..., osinfo=...): ...
 def system_alias(system, release, version): ...
-def architecture(executable=..., bits='', linkage=''): ...
+def architecture(executable=..., bits=..., linkage=...): ...
 def uname(): ...
 def system(): ...
 def node(): ...

stdlib/2.7/rfc822.pyi

@@ -1,6 +1,6 @@
 # Stubs for rfc822 (Python 2)
 #
-# NOTE: This dynamically typed stub was automatically generated by stubgen.
+# Based on stub generated by stubgen.
 
 from typing import Any
 
@@ -33,7 +33,7 @@ class Message:
     def __getitem__(self, name): ...
     def __setitem__(self, name, value): ...
     def __delitem__(self, name): ...
-    def setdefault(self, name, default=''): ...
+    def setdefault(self, name, default=...): ...
     def has_key(self, name): ...
     def __contains__(self, name): ...
     def __iter__(self): ...

tests/pytype_blacklist.txt

@@ -1,20 +1,15 @@
 # Pytype blacklist. Files will not be tested with pytype.
 
-2.7/Cookie.pyi
 2.7/StringIO.pyi
 2.7/__builtin__.pyi
 2.7/argparse.pyi
 2.7/builtins.pyi
-2.7/calendar.pyi
 2.7/codecs.pyi
-2.7/email/utils.pyi
 2.7/functools.pyi
 2.7/inspect.pyi
 2.7/logging/__init__.pyi
 2.7/os/__init__.pyi
-2.7/platform.pyi
 2.7/resource.pyi
-2.7/rfc822.pyi
 2.7/simplejson/__init__.pyi
 2.7/socket.pyi
 2.7/sqlite3/dbapi2.pyi