From 024ac542d738f56b36bdeb3517a10e93da5acab9 Mon Sep 17 00:00:00 2001 From: Nick Drozd Date: Sat, 26 Nov 2022 16:33:25 -0600 Subject: [PATCH] bpo-45975: Simplify some while-loops with walrus operator (GH-29347) --- Lib/_pyio.py | 5 +---- Lib/base64.py | 15 +++------------ Lib/ctypes/_aix.py | 8 ++------ Lib/email/parser.py | 5 +---- Lib/ftplib.py | 10 ++-------- Lib/http/client.py | 16 +++------------- Lib/http/cookiejar.py | 9 ++------- Lib/mailbox.py | 5 +---- Lib/mailcap.py | 4 +--- Lib/mimetypes.py | 5 +---- Lib/pstats.py | 2 -- Lib/pydoc.py | 4 +--- Lib/quopri.py | 9 ++------- Lib/shlex.py | 5 +---- Lib/shutil.py | 5 +---- Lib/smtplib.py | 5 +---- Lib/socketserver.py | 3 +-- Lib/tarfile.py | 12 +++--------- Lib/test/test_lzma.py | 20 ++++---------------- Lib/urllib/request.py | 10 ++-------- Lib/wsgiref/handlers.py | 5 +---- Lib/wsgiref/validate.py | 5 +---- Lib/xdrlib.py | 4 +--- Lib/xml/dom/expatbuilder.py | 5 +---- Lib/xml/etree/ElementTree.py | 5 +---- Lib/xml/sax/xmlreader.py | 4 +--- Lib/xmlrpc/client.py | 5 +---- Lib/xmlrpc/server.py | 4 +--- 28 files changed, 41 insertions(+), 153 deletions(-) diff --git a/Lib/_pyio.py b/Lib/_pyio.py index 163cf9de279ff0..7f247ff47c9e61 100644 --- a/Lib/_pyio.py +++ b/Lib/_pyio.py @@ -638,10 +638,7 @@ def read(self, size=-1): def readall(self): """Read until EOF, using multiple read() call.""" res = bytearray() - while True: - data = self.read(DEFAULT_BUFFER_SIZE) - if not data: - break + while data := self.read(DEFAULT_BUFFER_SIZE): res += data if res: return bytes(res) diff --git a/Lib/base64.py b/Lib/base64.py index 30796a6fd6d05a..95dc7b0086051b 100755 --- a/Lib/base64.py +++ b/Lib/base64.py @@ -508,14 +508,8 @@ def b85decode(b): def encode(input, output): """Encode a file; input and output are binary files.""" - while True: - s = input.read(MAXBINSIZE) - if not s: - break - while len(s) < MAXBINSIZE: - ns = input.read(MAXBINSIZE-len(s)) - if not ns: - break + while s := input.read(MAXBINSIZE): + while len(s) < MAXBINSIZE and (ns := input.read(MAXBINSIZE-len(s))): s += ns line = binascii.b2a_base64(s) output.write(line) @@ -523,10 +517,7 @@ def encode(input, output): def decode(input, output): """Decode a file; input and output are binary files.""" - while True: - line = input.readline() - if not line: - break + while line := input.readline(): s = binascii.a2b_base64(line) output.write(s) diff --git a/Lib/ctypes/_aix.py b/Lib/ctypes/_aix.py index fc3e95cbcc88a5..ee790f713a9ee3 100644 --- a/Lib/ctypes/_aix.py +++ b/Lib/ctypes/_aix.py @@ -108,12 +108,8 @@ def get_ld_headers(file): p = Popen(["/usr/bin/dump", f"-X{AIX_ABI}", "-H", file], universal_newlines=True, stdout=PIPE, stderr=DEVNULL) # be sure to read to the end-of-file - getting all entries - while True: - ld_header = get_ld_header(p) - if ld_header: - ldr_headers.append((ld_header, get_ld_header_info(p))) - else: - break + while ld_header := get_ld_header(p): + ldr_headers.append((ld_header, get_ld_header_info(p))) p.stdout.close() p.wait() return ldr_headers diff --git a/Lib/email/parser.py b/Lib/email/parser.py index 7db4da1ff081c1..e94d455baa5262 100644 --- a/Lib/email/parser.py +++ b/Lib/email/parser.py @@ -49,10 +49,7 @@ def parse(self, fp, headersonly=False): feedparser = FeedParser(self._class, policy=self.policy) if headersonly: feedparser._set_headersonly() - while True: - data = fp.read(8192) - if not data: - break + while data := fp.read(8192): feedparser.feed(data) return feedparser.close() diff --git a/Lib/ftplib.py b/Lib/ftplib.py index c7ca8f632e1bd4..a56e0c3085701b 100644 --- a/Lib/ftplib.py +++ b/Lib/ftplib.py @@ -434,10 +434,7 @@ def retrbinary(self, cmd, callback, blocksize=8192, rest=None): """ self.voidcmd('TYPE I') with self.transfercmd(cmd, rest) as conn: - while 1: - data = conn.recv(blocksize) - if not data: - break + while data := conn.recv(blocksize): callback(data) # shutdown ssl layer if _SSLSocket is not None and isinstance(conn, _SSLSocket): @@ -496,10 +493,7 @@ def storbinary(self, cmd, fp, blocksize=8192, callback=None, rest=None): """ self.voidcmd('TYPE I') with self.transfercmd(cmd, rest) as conn: - while 1: - buf = fp.read(blocksize) - if not buf: - break + while buf := fp.read(blocksize): conn.sendall(buf) if callback: callback(buf) diff --git a/Lib/http/client.py b/Lib/http/client.py index 0a3e950c669622..15c5cf634cf508 100644 --- a/Lib/http/client.py +++ b/Lib/http/client.py @@ -578,11 +578,7 @@ def _read_chunked(self, amt=None): assert self.chunked != _UNKNOWN value = [] try: - while True: - chunk_left = self._get_chunk_left() - if chunk_left is None: - break - + while (chunk_left := self._get_chunk_left()) is not None: if amt is not None and amt <= chunk_left: value.append(self._safe_read(amt)) self.chunk_left = chunk_left - amt @@ -998,10 +994,7 @@ def send(self, data): encode = self._is_textIO(data) if encode and self.debuglevel > 0: print("encoding file using iso-8859-1") - while 1: - datablock = data.read(self.blocksize) - if not datablock: - break + while datablock := data.read(self.blocksize): if encode: datablock = datablock.encode("iso-8859-1") sys.audit("http.client.send", self, datablock) @@ -1031,10 +1024,7 @@ def _read_readable(self, readable): encode = self._is_textIO(readable) if encode and self.debuglevel > 0: print("encoding file using iso-8859-1") - while True: - datablock = readable.read(self.blocksize) - if not datablock: - break + while datablock := readable.read(self.blocksize): if encode: datablock = datablock.encode("iso-8859-1") yield datablock diff --git a/Lib/http/cookiejar.py b/Lib/http/cookiejar.py index 65c45e2b17dfc0..b0161a86fdbb51 100644 --- a/Lib/http/cookiejar.py +++ b/Lib/http/cookiejar.py @@ -1915,9 +1915,7 @@ def _really_load(self, f, filename, ignore_discard, ignore_expires): "comment", "commenturl") try: - while 1: - line = f.readline() - if line == "": break + while (line := f.readline()) != "": if not line.startswith(header): continue line = line[len(header):].strip() @@ -2017,12 +2015,9 @@ def _really_load(self, f, filename, ignore_discard, ignore_expires): filename) try: - while 1: - line = f.readline() + while (line := f.readline()) != "": rest = {} - if line == "": break - # httponly is a cookie flag as defined in rfc6265 # when encoded in a netscape cookie file, # the line is prepended with "#HttpOnly_" diff --git a/Lib/mailbox.py b/Lib/mailbox.py index 70da07ed2e9e8b..59834a2b3b5243 100644 --- a/Lib/mailbox.py +++ b/Lib/mailbox.py @@ -1956,10 +1956,7 @@ def readlines(self, sizehint=None): def __iter__(self): """Iterate over lines.""" - while True: - line = self.readline() - if not line: - return + while line := self.readline(): yield line def tell(self): diff --git a/Lib/mailcap.py b/Lib/mailcap.py index 7278ea7051fccf..2f4656e854b3bb 100644 --- a/Lib/mailcap.py +++ b/Lib/mailcap.py @@ -90,9 +90,7 @@ def _readmailcapfile(fp, lineno): the viewing command is stored with the key "view". """ caps = {} - while 1: - line = fp.readline() - if not line: break + while line := fp.readline(): # Ignore comments and blank lines if line[0] == '#' or line.strip() == '': continue diff --git a/Lib/mimetypes.py b/Lib/mimetypes.py index 3224363a3f2bfb..37228de4828de5 100644 --- a/Lib/mimetypes.py +++ b/Lib/mimetypes.py @@ -217,10 +217,7 @@ def readfp(self, fp, strict=True): list of standard types, else to the list of non-standard types. """ - while 1: - line = fp.readline() - if not line: - break + while line := fp.readline(): words = line.split() for i in range(len(words)): if words[i][0] == '#': diff --git a/Lib/pstats.py b/Lib/pstats.py index 80408313e8b27f..51bcca84188740 100644 --- a/Lib/pstats.py +++ b/Lib/pstats.py @@ -223,8 +223,6 @@ def get_sort_arg_defs(self): for word, tup in self.sort_arg_dict_default.items(): fragment = word while fragment: - if not fragment: - break if fragment in dict: bad_list[fragment] = 0 break diff --git a/Lib/pydoc.py b/Lib/pydoc.py index c79ec77a8c09e4..0a693f45230c93 100755 --- a/Lib/pydoc.py +++ b/Lib/pydoc.py @@ -686,9 +686,7 @@ def markup(self, text, escape=None, funcs={}, classes={}, methods={}): r'RFC[- ]?(\d+)|' r'PEP[- ]?(\d+)|' r'(self\.)?(\w+))') - while True: - match = pattern.search(text, here) - if not match: break + while match := pattern.search(text, here): start, end = match.span() results.append(escape(text[here:start])) diff --git a/Lib/quopri.py b/Lib/quopri.py index 08899c5cb73a30..f36cf7b3951cda 100755 --- a/Lib/quopri.py +++ b/Lib/quopri.py @@ -67,10 +67,7 @@ def write(s, output=output, lineEnd=b'\n'): output.write(s + lineEnd) prevline = None - while 1: - line = input.readline() - if not line: - break + while line := input.readline(): outline = [] # Strip off any readline induced trailing newline stripped = b'' @@ -126,9 +123,7 @@ def decode(input, output, header=False): return new = b'' - while 1: - line = input.readline() - if not line: break + while line := input.readline(): i, n = 0, len(line) if n > 0 and line[n-1:n] == b'\n': partial = 0; n = n-1 diff --git a/Lib/shlex.py b/Lib/shlex.py index a91c9b022627b1..f4821616b62a0f 100644 --- a/Lib/shlex.py +++ b/Lib/shlex.py @@ -333,10 +333,7 @@ def quote(s): def _print_tokens(lexer): - while 1: - tt = lexer.get_token() - if not tt: - break + while tt := lexer.get_token(): print("Token: " + repr(tt)) if __name__ == '__main__': diff --git a/Lib/shutil.py b/Lib/shutil.py index f372406a6c51a8..867925aa10cc04 100644 --- a/Lib/shutil.py +++ b/Lib/shutil.py @@ -194,10 +194,7 @@ def copyfileobj(fsrc, fdst, length=0): # Localize variable access to minimize overhead. fsrc_read = fsrc.read fdst_write = fdst.write - while True: - buf = fsrc_read(length) - if not buf: - break + while buf := fsrc_read(length): fdst_write(buf) def _samefile(src, dst): diff --git a/Lib/smtplib.py b/Lib/smtplib.py index 05d2f8ccd73c98..18c91746fd7bf2 100755 --- a/Lib/smtplib.py +++ b/Lib/smtplib.py @@ -1099,10 +1099,7 @@ def prompt(prompt): toaddrs = prompt("To").split(',') print("Enter message, end with ^D:") msg = '' - while 1: - line = sys.stdin.readline() - if not line: - break + while line := sys.stdin.readline(): msg = msg + line print("Message length is %d" % len(msg)) diff --git a/Lib/socketserver.py b/Lib/socketserver.py index 30a5cfa59fe05b..842d526b011911 100644 --- a/Lib/socketserver.py +++ b/Lib/socketserver.py @@ -292,8 +292,7 @@ def handle_request(self): selector.register(self, selectors.EVENT_READ) while True: - ready = selector.select(timeout) - if ready: + if selector.select(timeout): return self._handle_request_noblock() else: if timeout is not None: diff --git a/Lib/tarfile.py b/Lib/tarfile.py index b47015f5cb6be5..d686435d90ad1b 100755 --- a/Lib/tarfile.py +++ b/Lib/tarfile.py @@ -1262,11 +1262,7 @@ def _proc_pax(self, tarfile): # the newline. keyword and value are both UTF-8 encoded strings. regex = re.compile(br"(\d+) ([^=]+)=") pos = 0 - while True: - match = regex.match(buf, pos) - if not match: - break - + while match := regex.match(buf, pos): length, keyword = match.groups() length = int(length) if length == 0: @@ -2418,10 +2414,8 @@ def _load(self): """Read through the entire archive file and look for readable members. """ - while True: - tarinfo = self.next() - if tarinfo is None: - break + while self.next() is not None: + pass self._loaded = True def _check(self, mode=None): diff --git a/Lib/test/test_lzma.py b/Lib/test/test_lzma.py index 145c8cfced4080..18f474ba2a8bdc 100644 --- a/Lib/test/test_lzma.py +++ b/Lib/test/test_lzma.py @@ -825,10 +825,7 @@ def test_read_0(self): def test_read_10(self): with LZMAFile(BytesIO(COMPRESSED_XZ)) as f: chunks = [] - while True: - result = f.read(10) - if not result: - break + while result := f.read(10): self.assertLessEqual(len(result), 10) chunks.append(result) self.assertEqual(b"".join(chunks), INPUT) @@ -911,10 +908,7 @@ def test_read_bad_data(self): def test_read1(self): with LZMAFile(BytesIO(COMPRESSED_XZ)) as f: blocks = [] - while True: - result = f.read1() - if not result: - break + while result := f.read1(): blocks.append(result) self.assertEqual(b"".join(blocks), INPUT) self.assertEqual(f.read1(), b"") @@ -926,10 +920,7 @@ def test_read1_0(self): def test_read1_10(self): with LZMAFile(BytesIO(COMPRESSED_XZ)) as f: blocks = [] - while True: - result = f.read1(10) - if not result: - break + while result := f.read1(10): blocks.append(result) self.assertEqual(b"".join(blocks), INPUT) self.assertEqual(f.read1(), b"") @@ -937,10 +928,7 @@ def test_read1_10(self): def test_read1_multistream(self): with LZMAFile(BytesIO(COMPRESSED_XZ * 5)) as f: blocks = [] - while True: - result = f.read1() - if not result: - break + while result := f.read1(): blocks.append(result) self.assertEqual(b"".join(blocks), INPUT * 5) self.assertEqual(f.read1(), b"") diff --git a/Lib/urllib/request.py b/Lib/urllib/request.py index 278aa3a14bfeea..151034e6a81bf9 100644 --- a/Lib/urllib/request.py +++ b/Lib/urllib/request.py @@ -265,10 +265,7 @@ def urlretrieve(url, filename=None, reporthook=None, data=None): if reporthook: reporthook(blocknum, bs, size) - while True: - block = fp.read(bs) - if not block: - break + while block := fp.read(bs): read += len(block) tfp.write(block) blocknum += 1 @@ -1847,10 +1844,7 @@ def retrieve(self, url, filename=None, reporthook=None, data=None): size = int(headers["Content-Length"]) if reporthook: reporthook(blocknum, bs, size) - while 1: - block = fp.read(bs) - if not block: - break + while block := fp.read(bs): read += len(block) tfp.write(block) blocknum += 1 diff --git a/Lib/wsgiref/handlers.py b/Lib/wsgiref/handlers.py index cd0916dc5553fb..cafe872c7aae9b 100644 --- a/Lib/wsgiref/handlers.py +++ b/Lib/wsgiref/handlers.py @@ -475,10 +475,7 @@ def _write(self,data): from warnings import warn warn("SimpleHandler.stdout.write() should not do partial writes", DeprecationWarning) - while True: - data = data[result:] - if not data: - break + while data := data[result:]: result = self.stdout.write(data) def _flush(self): diff --git a/Lib/wsgiref/validate.py b/Lib/wsgiref/validate.py index 6044e320a474c6..1a1853cd63a0d2 100644 --- a/Lib/wsgiref/validate.py +++ b/Lib/wsgiref/validate.py @@ -214,10 +214,7 @@ def readlines(self, *args): return lines def __iter__(self): - while 1: - line = self.readline() - if not line: - return + while line := self.readline(): yield line def close(self): diff --git a/Lib/xdrlib.py b/Lib/xdrlib.py index b56ffa59b73dcb..f8c2c18228da4d 100644 --- a/Lib/xdrlib.py +++ b/Lib/xdrlib.py @@ -224,9 +224,7 @@ def unpack_string(self): def unpack_list(self, unpack_item): list = [] - while 1: - x = self.unpack_uint() - if x == 0: break + while (x := self.unpack_uint()) != 0: if x != 1: raise ConversionError('0 or 1 expected, got %r' % (x,)) item = unpack_item() diff --git a/Lib/xml/dom/expatbuilder.py b/Lib/xml/dom/expatbuilder.py index 199c22d0af347e..7dd667bf3fbe04 100644 --- a/Lib/xml/dom/expatbuilder.py +++ b/Lib/xml/dom/expatbuilder.py @@ -200,10 +200,7 @@ def parseFile(self, file): parser = self.getParser() first_buffer = True try: - while 1: - buffer = file.read(16*1024) - if not buffer: - break + while buffer := file.read(16*1024): parser.Parse(buffer, False) if first_buffer and self.document.documentElement: self._setup_subset(buffer) diff --git a/Lib/xml/etree/ElementTree.py b/Lib/xml/etree/ElementTree.py index ebbe2b703bfd8f..df5d5191126ae1 100644 --- a/Lib/xml/etree/ElementTree.py +++ b/Lib/xml/etree/ElementTree.py @@ -566,10 +566,7 @@ def parse(self, source, parser=None): # it with chunks. self._root = parser._parse_whole(source) return self._root - while True: - data = source.read(65536) - if not data: - break + while data := source.read(65536): parser.feed(data) self._root = parser.close() return self._root diff --git a/Lib/xml/sax/xmlreader.py b/Lib/xml/sax/xmlreader.py index 716f22840414e6..e906121d23b9ef 100644 --- a/Lib/xml/sax/xmlreader.py +++ b/Lib/xml/sax/xmlreader.py @@ -120,10 +120,8 @@ def parse(self, source): file = source.getCharacterStream() if file is None: file = source.getByteStream() - buffer = file.read(self._bufsize) - while buffer: + while buffer := file.read(self._bufsize): self.feed(buffer) - buffer = file.read(self._bufsize) self.close() def feed(self, data): diff --git a/Lib/xmlrpc/client.py b/Lib/xmlrpc/client.py index bef23f4505e03c..ea8da766cb5a7e 100644 --- a/Lib/xmlrpc/client.py +++ b/Lib/xmlrpc/client.py @@ -1339,10 +1339,7 @@ def parse_response(self, response): p, u = self.getparser() - while 1: - data = stream.read(1024) - if not data: - break + while data := stream.read(1024): if self.verbose: print("body:", repr(data)) p.feed(data) diff --git a/Lib/xmlrpc/server.py b/Lib/xmlrpc/server.py index 0c4b558045a9f4..4dddb1d10e08bd 100644 --- a/Lib/xmlrpc/server.py +++ b/Lib/xmlrpc/server.py @@ -720,9 +720,7 @@ def markup(self, text, escape=None, funcs={}, classes={}, methods={}): r'RFC[- ]?(\d+)|' r'PEP[- ]?(\d+)|' r'(self\.)?((?:\w|\.)+))\b') - while 1: - match = pattern.search(text, here) - if not match: break + while match := pattern.search(text, here): start, end = match.span() results.append(escape(text[here:start]))