Update stub for csv (#1398)

stdlib/2and3/csv.pyi

@@ -0,0 +1,73 @@
+from collections import OrderedDict
+import sys
+from typing import Any, Dict, Iterable, Iterator, List, Optional, Sequence, Union
+
+from _csv import _reader, _writer, reader as reader, writer as writer, register_dialect as register_dialect, unregister_dialect as unregister_dialect, get_dialect as get_dialect, list_dialects as list_dialects, field_size_limit as field_size_limit, QUOTE_ALL as QUOTE_ALL, QUOTE_MINIMAL as QUOTE_MINIMAL, QUOTE_NONE as QUOTE_NONE, QUOTE_NONNUMERIC as QUOTE_NONNUMERIC, Error as Error
+
+_Dialect = Union[str, Dialect]
+_DictRow = Dict[str, Any]
+
+class Dialect:
+    delimiter = ...  # type: str
+    quotechar = ...  # type: Optional[str]
+    escapechar = ...  # type: Optional[str]
+    doublequote = ...  # type: bool
+    skipinitialspace = ...  # type: bool
+    lineterminator = ...  # type: str
+    quoting = ...  # type: int
+    def __init__(self) -> None: ...
+
+class excel(Dialect):
+    delimiter = ...  # type: str
+    quotechar = ...  # type: str
+    doublequote = ...  # type: bool
+    skipinitialspace = ...  # type: bool
+    lineterminator = ...  # type: str
+    quoting = ...  # type: int
+
+class excel_tab(excel):
+    delimiter = ...  # type: str
+
+if sys.version_info >= (3,):
+    class unix_dialect(Dialect):
+        delimiter = ...  # type: str
+        quotechar = ...  # type: str
+        doublequote = ...  # type: bool
+        skipinitialspace = ...  # type: bool
+        lineterminator = ...  # type: str
+        quoting = ...  # type: int
+
+if sys.version_info >= (3, 6):
+    class DictReader(Iterator[OrderedDict[str, str]]):
+        restkey = ...  # type: Optional[str]
+        restval = ...  # type: Optional[str]
+        reader = ...  # type: _reader
+        dialect = ...  # type: _Dialect
+        line_num = ...  # type: int
+        fieldnames = ...  # type: Sequence[str]
+        def __init__(self, f: Iterator[str], fieldnames: Sequence[str] = ..., restkey: Optional[str] = ..., restval: Optional[str] = ..., dialect: _Dialect = ..., *args: Any, **kwds: Any) -> None: ...
+else:
+    class DictReader(Iterator[Dict[str, str]]):
+        restkey = ...  # type: Optional[str]
+        restval = ...  # type: Optional[str]
+        reader = ...  # type: _reader
+        dialect = ...  # type: _Dialect
+        line_num = ...  # type: int
+        fieldnames = ...  # type: Sequence[str]
+        def __init__(self, f: Iterator[str], fieldnames: Sequence[str] = ..., restkey: Optional[str] = ..., restval: Optional[str] = ..., dialect: _Dialect = ..., *args: Any, **kwds: Any) -> None: ...
+
+class DictWriter:
+    fieldnames = ...  # type: Sequence[str]
+    restval = ...  # type: Optional[Any]
+    extrasaction = ...  # type: str
+    writer = ...  # type: _writer
+    def __init__(self, f: Any, fieldnames: Sequence[str], restval: Optional[Any], extrasaction: str = ..., dialect: _Dialect = ..., *args: Any, **kwds: Any) -> None: ...
+    def writeheader(self) -> None: ...
+    def writerow(self, rowdict: _DictRow) -> None: ...
+    def writerows(self, rowdicts: Iterable[_DictRow]) -> None: ...
+
+class Sniffer:
+    preferred = ...  # type: List[str]
+    def __init__(self) -> None: ...
+    def sniff(self, sample: str, delimiters: Optional[str] = ...) -> Dialect: ...
+    def has_header(self, sample: str) -> bool: ...