suboptimizations and some future safeguards

bin/u2c.py

@@ -1057,14 +1057,13 @@ class Ctl(object):
                 self.uploader_busy += 1
                 self.t0_up = self.t0_up or time.time()
 
-            zs = "{0}/{1}/{2}/{3} {4}/{5} {6}"
+            stats = "%d/%d/%d/%d %d/%d %s" % (
-            stats = zs.format(
                 self.up_f,
                 len(self.recheck),
                 self.uploader_busy,
                 self.nfiles - self.up_f,
-                int(self.nbytes / (1024 * 1024)),
+                self.nbytes // (1024 * 1024),
-                int((self.nbytes - self.up_b) / (1024 * 1024)),
+                (self.nbytes - self.up_b) // (1024 * 1024),
                 self.eta,
             )
 

copyparty/__main__.py

@@ -1432,7 +1432,7 @@ def main(argv: Optional[list[str]] = None) -> None:
 
         _, hard = resource.getrlimit(resource.RLIMIT_NOFILE)
         if hard > 0:  # -1 == infinite
-            nc = min(nc, hard // 4)
+            nc = min(nc, int(hard / 4))
     except:
         nc = 512
 

copyparty/broker_mpw.py

@@ -76,7 +76,7 @@ class MpWorker(BrokerCli):
         pass
 
     def logw(self, msg: str, c: Union[int, str] = 0) -> None:
-        self.log("mp{}".format(self.n), msg, c)
+        self.log("mp%d" % (self.n,), msg, c)
 
     def main(self) -> None:
         while True:

copyparty/httpcli.py

@@ -190,7 +190,7 @@ class HttpCli(object):
 
     def unpwd(self, m: Match[str]) -> str:
         a, b, c = m.groups()
-        return "{}\033[7m {} \033[27m{}".format(a, self.asrv.iacct[b], c)
+        return "%s\033[7m %s \033[27m%s" % (a, self.asrv.iacct[b], c)
 
     def _check_nonfatal(self, ex: Pebkac, post: bool) -> bool:
         if post:
@@ -557,16 +557,16 @@ class HttpCli(object):
                     self.keepalive = False
 
                 em = str(ex)
-                msg = em if pex == ex else min_ex()
+                msg = em if pex is ex else min_ex()
                 if pex.code != 404 or self.do_log:
                     self.log(
-                        "{}\033[0m, {}".format(msg, self.vpath),
+                        "%s\033[0m, %s" % (msg, self.vpath),
                         6 if em.startswith("client d/c ") else 3,
                     )
 
-                msg = "{}\r\nURL: {}\r\n".format(em, self.vpath)
+                msg = "%s\r\nURL: %s\r\n" % (em, self.vpath)
                 if self.hint:
-                    msg += "hint: {}\r\n".format(self.hint)
+                    msg += "hint: %s\r\n" % (self.hint,)
 
                 if "database is locked" in em:
                     self.conn.hsrv.broker.say("log_stacks")
@@ -809,7 +809,7 @@ class HttpCli(object):
             if k in skip:
                 continue
 
-            t = "{}={}".format(quotep(k), quotep(v))
+            t = "%s=%s" % (quotep(k), quotep(v))
             ret.append(t.replace(" ", "+").rstrip("="))
 
         if not ret:
@@ -857,7 +857,8 @@ class HttpCli(object):
         oh = self.out_headers
         origin = origin.lower()
         good_origins = self.args.acao + [
-            "{}://{}".format(
+            "%s://%s"
+            % (
                 "https" if self.is_https else "http",
                 self.host.lower().split(":")[0],
             )
@@ -1054,7 +1055,7 @@ class HttpCli(object):
             self.can_read = self.can_write = self.can_get = False
 
         if not self.can_read and not self.can_write and not self.can_get:
-            self.log("inaccessible: [{}]".format(self.vpath))
+            self.log("inaccessible: [%s]" % (self.vpath,))
             raise Pebkac(401, "authenticate")
 
         from .dxml import parse_xml
@@ -1404,7 +1405,7 @@ class HttpCli(object):
         if txt and len(txt) == orig_len:
             raise Pebkac(500, "chunk slicing failed")
 
-        buf = "{:x}\r\n".format(len(buf)).encode(enc) + buf
+        buf = ("%x\r\n" % (len(buf),)).encode(enc) + buf
         self.s.sendall(buf + b"\r\n")
         return txt
 
@@ -4231,7 +4232,7 @@ class HttpCli(object):
         if icur:
             lmte = list(mte)
             if self.can_admin:
-                lmte += ["up_ip", ".up_at"]
+                lmte.extend(("up_ip", ".up_at"))
 
             taglist = [k for k in lmte if k in tagset]
             for fe in dirs:

copyparty/httpconn.py

@@ -93,7 +93,7 @@ class HttpConn(object):
             self.rproxy = ip
 
         self.ip = ip
-        self.log_src = "{} \033[{}m{}".format(ip, color, self.addr[1]).ljust(26)
+        self.log_src = ("%s \033[%dm%d" % (ip, color, self.addr[1])).ljust(26)
         return self.log_src
 
     def respath(self, res_name: str) -> str:
@@ -176,7 +176,7 @@ class HttpConn(object):
 
                 self.s = ctx.wrap_socket(self.s, server_side=True)
                 msg = [
-                    "\033[1;3{:d}m{}".format(c, s)
+                    "\033[1;3%dm%s" % (c, s)
                     for c, s in zip([0, 5, 0], self.s.cipher())  # type: ignore
                 ]
                 self.log(" ".join(msg) + "\033[0m")

copyparty/httpsrv.py

@@ -366,7 +366,7 @@ class HttpSrv(object):
             if not self.t_periodic:
                 name = "hsrv-pt"
                 if self.nid:
-                    name += "-{}".format(self.nid)
+                    name += "-%d" % (self.nid,)
 
                 self.t_periodic = Daemon(self.periodic, name)
 
@@ -385,7 +385,7 @@ class HttpSrv(object):
 
         Daemon(
             self.thr_client,
-            "httpconn-{}-{}".format(addr[0].split(".", 2)[-1][-6:], addr[1]),
+            "httpconn-%s-%d" % (addr[0].split(".", 2)[-1][-6:], addr[1]),
             (sck, addr),
         )
 
@@ -402,9 +402,7 @@ class HttpSrv(object):
             try:
                 sck, addr = task
                 me = threading.current_thread()
-                me.name = "httpconn-{}-{}".format(
+                me.name = "httpconn-%s-%d" % (addr[0].split(".", 2)[-1][-6:], addr[1])
-                    addr[0].split(".", 2)[-1][-6:], addr[1]
-                )
                 self.thr_client(sck, addr)
                 me.name = self.name + "-poolw"
             except Exception as ex:

copyparty/ico.py

@@ -27,13 +27,13 @@ class Ico(object):
         c1 = colorsys.hsv_to_rgb(zb[0] / 256.0, 1, 0.3)
         c2 = colorsys.hsv_to_rgb(zb[0] / 256.0, 0.8 if HAVE_PILF else 1, 1)
         ci = [int(x * 255) for x in list(c1) + list(c2)]
-        c = "".join(["{:02x}".format(x) for x in ci])
+        c = "".join(["%02x" % (x,) for x in ci])
 
         w = 100
         h = 30
         if not self.args.th_no_crop and as_thumb:
             sw, sh = self.args.th_size.split("x")
-            h = int(100 / (float(sw) / float(sh)))
+            h = int(100.0 / (float(sw) / float(sh)))
             w = 100
 
         if chrome:
@@ -47,12 +47,12 @@ class Ico(object):
                     # [.lt] are hard to see lowercase / unspaced
                     ext2 = re.sub("(.)", "\\1 ", ext).upper()
 
-                    h = int(128 * h / w)
+                    h = int(128.0 * h / w)
                     w = 128
                     img = Image.new("RGB", (w, h), "#" + c[:6])
                     pb = ImageDraw.Draw(img)
                     _, _, tw, th = pb.textbbox((0, 0), ext2, font_size=16)
-                    xy = ((w - tw) // 2, (h - th) // 2)
+                    xy = (int((w - tw) / 2), int((h - th) / 2))
                     pb.text(xy, ext2, fill="#" + c[6:], font_size=16)
 
                     img = img.resize((w * 2, h * 2), Image.NEAREST)
@@ -68,7 +68,7 @@ class Ico(object):
                 # svg: 3s, cache: 6s, this: 8s
                 from PIL import Image, ImageDraw
 
-                h = int(64 * h / w)
+                h = int(64.0 * h / w)
                 w = 64
                 img = Image.new("RGB", (w, h), "#" + c[:6])
                 pb = ImageDraw.Draw(img)

copyparty/mtag.py

@@ -240,7 +240,7 @@ def parse_ffprobe(txt: str) -> tuple[dict[str, tuple[int, Any]], dict[str, list[
         if "/" in fps:
             fa, fb = fps.split("/")
             try:
-                fps = int(fa) * 1.0 / int(fb)
+                fps = float(fa) / float(fb)
             except:
                 fps = 9001
 

copyparty/star.py

@@ -65,21 +65,21 @@ class StreamTar(StreamArc):
             cmp = re.sub(r"[^a-z0-9]*pax[^a-z0-9]*", "", cmp)
 
         try:
-            cmp, lv = cmp.replace(":", ",").split(",")
+            cmp, zs = cmp.replace(":", ",").split(",")
-            lv = int(lv)
+            lv = int(zs)
         except:
-            lv = None
+            lv = -1
 
         arg = {"name": None, "fileobj": self.qfile, "mode": "w", "format": fmt}
         if cmp == "gz":
             fun = tarfile.TarFile.gzopen
-            arg["compresslevel"] = lv if lv is not None else 3
+            arg["compresslevel"] = lv if lv >= 0 else 3
         elif cmp == "bz2":
             fun = tarfile.TarFile.bz2open
-            arg["compresslevel"] = lv if lv is not None else 2
+            arg["compresslevel"] = lv if lv >= 0 else 2
         elif cmp == "xz":
             fun = tarfile.TarFile.xzopen
-            arg["preset"] = lv if lv is not None else 1
+            arg["preset"] = lv if lv >= 0 else 1
         else:
             fun = tarfile.open
             arg["mode"] = "w|"

copyparty/svchub.py

@@ -474,7 +474,7 @@ class SvcHub(object):
             import resource
 
             soft, hard = [
-                x if x > 0 else 1024 * 1024
+                int(x) if x > 0 else 1024 * 1024
                 for x in list(resource.getrlimit(resource.RLIMIT_NOFILE))
             ]
         except:
@@ -791,7 +791,7 @@ class SvcHub(object):
                 self.logf.flush()
 
             now = time.time()
-            if now >= self.next_day:
+            if int(now) >= self.next_day:
                 self._set_next_day()
 
     def _set_next_day(self) -> None:
@@ -819,7 +819,7 @@ class SvcHub(object):
         """handles logging from all components"""
         with self.log_mutex:
             now = time.time()
-            if now >= self.next_day:
+            if int(now) >= self.next_day:
                 dt = datetime.fromtimestamp(now, UTC)
                 zs = "{}\n" if self.no_ansi else "\033[36m{}\033[0m\n"
                 zs = zs.format(dt.strftime("%Y-%m-%d"))

copyparty/th_srv.py

@@ -102,7 +102,7 @@ def thumb_path(histpath: str, rem: str, mtime: float, fmt: str, ffa: set[str]) -
     rd += "\n" + fmt
     h = hashlib.sha512(afsenc(rd)).digest()
     b64 = base64.urlsafe_b64encode(h).decode("ascii")[:24]
-    rd = "{}/{}/".format(b64[:2], b64[2:4]).lower() + b64
+    rd = ("%s/%s/" % (b64[:2], b64[2:4])).lower() + b64
 
     # could keep original filenames but this is safer re pathlen
     h = hashlib.sha512(afsenc(fn)).digest()
@@ -115,7 +115,7 @@ def thumb_path(histpath: str, rem: str, mtime: float, fmt: str, ffa: set[str]) -
         fmt = "webp" if fc == "w" else "png" if fc == "p" else "jpg"
         cat = "th"
 
-    return "{}/{}/{}/{}.{:x}.{}".format(histpath, cat, rd, fn, int(mtime), fmt)
+    return "%s/%s/%s/%s.%x.%s" % (histpath, cat, rd, fn, int(mtime), fmt)
 
 
 class ThumbSrv(object):
@@ -382,7 +382,7 @@ class ThumbSrv(object):
                 # method 0 = pillow-default, fast
                 # method 4 = ffmpeg-default
                 # method 6 = max, slow
-                fmts += ["RGBA", "LA"]
+                fmts.extend(("RGBA", "LA"))
                 args["method"] = 6
             else:
                 # default q = 75

copyparty/up2k.py

@@ -987,7 +987,7 @@ class Up2k(object):
                 excl = [x.replace("/", "\\") for x in excl]
             else:
                 # ~/.wine/dosdevices/z:/ and such
-                excl += ["/dev", "/proc", "/run", "/sys"]
+                excl.extend(("/dev", "/proc", "/run", "/sys"))
 
             rtop = absreal(top)
             n_add = n_rm = 0
@@ -1089,7 +1089,7 @@ class Up2k(object):
         cv = ""
 
         assert self.pp and self.mem_cur
-        self.pp.msg = "a{} {}".format(self.pp.n, cdir)
+        self.pp.msg = "a%d %s" % (self.pp.n, cdir)
 
         rd = cdir[len(top) :].strip("/")
         if WINDOWS:
@@ -1164,8 +1164,8 @@ class Up2k(object):
                     continue
 
                 if not sz and (
-                    "{}.PARTIAL".format(iname) in partials
+                    "%s.PARTIAL" % (iname,) in partials
-                    or ".{}.PARTIAL".format(iname) in partials
+                    or ".%s.PARTIAL" % (iname,) in partials
                 ):
                     # placeholder for unfinished upload
                     continue
@@ -1261,7 +1261,7 @@ class Up2k(object):
             else:
                 at = 0
 
-            self.pp.msg = "a{} {}".format(self.pp.n, abspath)
+            self.pp.msg = "a%d %s" % (self.pp.n, abspath)
 
             if nohash or not sz:
                 wark = up2k_wark_from_metadata(self.salt, sz, lmod, rd, fn)
@@ -1361,7 +1361,7 @@ class Up2k(object):
                 rd = drd
 
             abspath = djoin(top, rd)
-            self.pp.msg = "b{} {}".format(ndirs - nchecked, abspath)
+            self.pp.msg = "b%d %s" % (ndirs - nchecked, abspath)
             try:
                 if os.path.isdir(abspath):
                     continue
@@ -1713,7 +1713,7 @@ class Up2k(object):
                     cur.execute(q, (w[:16],))
 
             abspath = djoin(ptop, rd, fn)
-            self.pp.msg = "c{} {}".format(nq, abspath)
+            self.pp.msg = "c%d %s" % (nq, abspath)
             if not mpool:
                 n_tags = self._tagscan_file(cur, entags, w, abspath, ip, at)
             else:
@@ -1770,7 +1770,7 @@ class Up2k(object):
                     if c2.execute(q, (row[0][:16],)).fetchone():
                         continue
 
-                gf.write("{}\n".format("\x00".join(row)).encode("utf-8"))
+                gf.write(("%s\n" % ("\x00".join(row),)).encode("utf-8"))
                 n += 1
 
         c2.close()
@@ -2700,7 +2700,7 @@ class Up2k(object):
         else:
             dip = self.hub.iphash.s(ip)
 
-        suffix = "-{:.6f}-{}".format(ts, dip)
+        suffix = "-%.6f-%s" % (ts, dip)
         with ren_open(fname, "wb", fdir=fdir, suffix=suffix) as zfw:
             return zfw["orz"][1]
 
@@ -2915,7 +2915,7 @@ class Up2k(object):
         except:
             pass
 
-        z2 += [upt]
+        z2.append(upt)
         if self.idx_wark(vflags, *z2):
             del self.registry[ptop][wark]
         else:
@@ -3208,9 +3208,9 @@ class Up2k(object):
                     except:
                         pass
 
-                volpath = "{}/{}".format(vrem, fn).strip("/")
+                volpath = ("%s/%s" % (vrem, fn)).strip("/")
-                vpath = "{}/{}".format(dbv.vpath, volpath).strip("/")
+                vpath = ("%s/%s" % (dbv.vpath, volpath)).strip("/")
-                self.log("rm {}\n  {}".format(vpath, abspath))
+                self.log("rm %s\n  %s" % (vpath, abspath))
                 _ = dbv.get(volpath, uname, *permsets[0])
                 if xbd:
                     if not runhook(
@@ -3742,7 +3742,7 @@ class Up2k(object):
                     return []
 
                 if self.pp:
-                    mb = int(fsz / 1024 / 1024)
+                    mb = fsz // (1024 * 1024)
                     self.pp.msg = prefix + str(mb) + suffix
 
                 hashobj = hashlib.sha512()
@@ -3807,7 +3807,7 @@ class Up2k(object):
         else:
             dip = self.hub.iphash.s(job["addr"])
 
-        suffix = "-{:.6f}-{}".format(job["t0"], dip)
+        suffix = "-%.6f-%s" % (job["t0"], dip)
         with ren_open(tnam, "wb", fdir=pdir, suffix=suffix) as zfw:
             f, job["tnam"] = zfw["orz"]
             abspath = djoin(pdir, job["tnam"])
@@ -4138,6 +4138,6 @@ def up2k_wark_from_hashlist(salt: str, filesize: int, hashes: list[str]) -> str:
 
 
 def up2k_wark_from_metadata(salt: str, sz: int, lastmod: int, rd: str, fn: str) -> str:
-    ret = sfsenc("{}\n{}\n{}\n{}\n{}".format(salt, lastmod, sz, rd, fn))
+    ret = sfsenc("%s\n%d\n%d\n%s\n%s" % (salt, lastmod, sz, rd, fn))
     ret = base64.urlsafe_b64encode(hashlib.sha512(ret).digest())
-    return "#{}".format(ret.decode("ascii"))[:44]
+    return ("#%s" % (ret.decode("ascii"),))[:44]

copyparty/util.py

@@ -849,7 +849,7 @@ class MTHash(object):
                     ex = ex or str(qe)
 
                 if pp:
-                    mb = int((fsz - nch * chunksz) / 1024 / 1024)
+                    mb = (fsz - nch * chunksz) // (1024 * 1024)
                     pp.msg = prefix + str(mb) + suffix
 
             if ex:
@@ -1071,7 +1071,7 @@ def uprint(msg: str) -> None:
 
 
 def nuprint(msg: str) -> None:
-    uprint("{}\n".format(msg))
+    uprint("%s\n" % (msg,))
 
 
 def dedent(txt: str) -> str:
@@ -1094,10 +1094,10 @@ def rice_tid() -> str:
 def trace(*args: Any, **kwargs: Any) -> None:
     t = time.time()
     stack = "".join(
-        "\033[36m{}\033[33m{}".format(x[0].split(os.sep)[-1][:-3], x[1])
+        "\033[36m%s\033[33m%s" % (x[0].split(os.sep)[-1][:-3], x[1])
         for x in traceback.extract_stack()[3:-1]
     )
-    parts = ["{:.6f}".format(t), rice_tid(), stack]
+    parts = ["%.6f" % (t,), rice_tid(), stack]
 
     if args:
         parts.append(repr(args))
@@ -1114,17 +1114,17 @@ def alltrace() -> str:
     threads: dict[str, types.FrameType] = {}
     names = dict([(t.ident, t.name) for t in threading.enumerate()])
     for tid, stack in sys._current_frames().items():
-        name = "{} ({:x})".format(names.get(tid), tid)
+        name = "%s (%x)" % (names.get(tid), tid)
         threads[name] = stack
 
     rret: list[str] = []
     bret: list[str] = []
     for name, stack in sorted(threads.items()):
-        ret = ["\n\n# {}".format(name)]
+        ret = ["\n\n# %s" % (name,)]
         pad = None
         for fn, lno, name, line in traceback.extract_stack(stack):
             fn = os.sep.join(fn.split(os.sep)[-3:])
-            ret.append('File: "{}", line {}, in {}'.format(fn, lno, name))
+            ret.append('File: "%s", line %d, in %s' % (fn, lno, name))
             if line:
                 ret.append("  " + str(line.strip()))
                 if "self.not_empty.wait()" in line:
@@ -1133,7 +1133,7 @@ def alltrace() -> str:
         if pad:
             bret += [ret[0]] + [pad + x for x in ret[1:]]
         else:
-            rret += ret
+            rret.extend(ret)
 
     return "\n".join(rret + bret) + "\n"
 
@@ -1229,9 +1229,9 @@ def vol_san(vols: list["VFS"], txt: bytes) -> bytes:
 def min_ex(max_lines: int = 8, reverse: bool = False) -> str:
     et, ev, tb = sys.exc_info()
     stb = traceback.extract_tb(tb)
-    fmt = "{} @ {} <{}>: {}"
+    fmt = "%s @ %d <%s>: %s"
-    ex = [fmt.format(fp.split(os.sep)[-1], ln, fun, txt) for fp, ln, fun, txt in stb]
+    ex = [fmt % (fp.split(os.sep)[-1], ln, fun, txt) for fp, ln, fun, txt in stb]
-    ex.append("[{}] {}".format(et.__name__ if et else "(anonymous)", ev))
+    ex.append("[%s] %s" % (et.__name__ if et else "(anonymous)", ev))
     return "\n".join(ex[-max_lines:][:: -1 if reverse else 1])
 
 
@@ -1282,7 +1282,7 @@ def ren_open(
             with fun(fsenc(fpath), *args, **kwargs) as f:
                 if b64:
                     assert fdir
-                    fp2 = "fn-trunc.{}.txt".format(b64)
+                    fp2 = "fn-trunc.%s.txt" % (b64,)
                     fp2 = os.path.join(fdir, fp2)
                     with open(fsenc(fp2), "wb") as f2:
                         f2.write(orig_name.encode("utf-8"))
@@ -1311,7 +1311,7 @@ def ren_open(
                 raise
 
         if not b64:
-            zs = "{}\n{}".format(orig_name, suffix).encode("utf-8", "replace")
+            zs = ("%s\n%s" % (orig_name, suffix)).encode("utf-8", "replace")
             zs = hashlib.sha512(zs).digest()[:12]
             b64 = base64.urlsafe_b64encode(zs).decode("utf-8")
 
@@ -1331,7 +1331,7 @@ def ren_open(
                     # okay do the first letter then
                     ext = "." + ext[2:]
 
-            fname = "{}~{}{}".format(bname, b64, ext)
+            fname = "%s~%s%s" % (bname, b64, ext)
 
 
 class MultipartParser(object):
@@ -1608,7 +1608,7 @@ def rand_name(fdir: str, fn: str, rnd: int) -> str:
                 break
 
             nc = rnd + extra
-            nb = int((6 + 6 * nc) / 8)
+            nb = (6 + 6 * nc) // 8
             zb = os.urandom(nb)
             zb = base64.urlsafe_b64encode(zb)
             fn = zb[:nc].decode("utf-8") + ext
@@ -1711,7 +1711,7 @@ def get_spd(nbyte: int, t0: float, t: Optional[float] = None) -> str:
     bps = nbyte / ((t - t0) + 0.001)
     s1 = humansize(nbyte).replace(" ", "\033[33m").replace("iB", "")
     s2 = humansize(bps).replace(" ", "\033[35m").replace("iB", "")
-    return "{} \033[0m{}/s\033[0m".format(s1, s2)
+    return "%s \033[0m%s/s\033[0m" % (s1, s2)
 
 
 def s2hms(s: float, optional_h: bool = False) -> str:
@@ -1719,9 +1719,9 @@ def s2hms(s: float, optional_h: bool = False) -> str:
     h, s = divmod(s, 3600)
     m, s = divmod(s, 60)
     if not h and optional_h:
-        return "{}:{:02}".format(m, s)
+        return "%d:%02d" % (m, s)
 
-    return "{}:{:02}:{:02}".format(h, m, s)
+    return "%d:%02d:%02d" % (h, m, s)
 
 
 def djoin(*paths: str) -> str:
@@ -2191,7 +2191,7 @@ def read_socket_chunked(
             raise Pebkac(400, t.format(x))
 
         if log:
-            log("receiving {} byte chunk".format(chunklen))
+            log("receiving %d byte chunk" % (chunklen,))
 
         for chunk in read_socket(sr, chunklen):
             yield chunk
@@ -2964,7 +2964,7 @@ def visual_length(txt: str) -> int:
                 pend = None
             else:
                 if ch == "\033":
-                    pend = "{0}".format(ch)
+                    pend = "%s" % (ch,)
                 else:
                     co = ord(ch)
                     # the safe parts of latin1 and cp437 (no greek stuff)

scripts/sfx.py

@@ -262,7 +262,7 @@ def unpack():
     final = opj(top, name)
     san = opj(final, "copyparty/up2k.py")
     for suf in range(0, 9001):
-        withpid = "{}.{}.{}".format(name, os.getpid(), suf)
+        withpid = "%s.%d.%s" % (name, os.getpid(), suf)
         mine = opj(top, withpid)
         if not ofe(mine):
             break
@@ -285,8 +285,8 @@ def unpack():
 
     ck = hashfile(tar)
     if ck != CKSUM:
-        t = "\n\nexpected {} ({} byte)\nobtained {} ({} byte)\nsfx corrupt"
+        t = "\n\nexpected %s (%d byte)\nobtained %s (%d byte)\nsfx corrupt"
-        raise Exception(t.format(CKSUM, SIZE, ck, sz))
+        raise Exception(t % (CKSUM, SIZE, ck, sz))
 
     with tarfile.open(tar, "r:bz2") as tf:
         # this is safe against traversal