Add reindent.py script

reindent.py

@@ -1,18 +1,333 @@
-# reindent.py
+#! /usr/bin/env python3
+
+# Released to the public domain, by Tim Peters, 03 October 2000.
+
+"""reindent [-d][-r][-v] [ path ... ]
+
+-d (--dryrun)   Dry run.   Analyze, but don't make any changes to, files.
+-r (--recurse)  Recurse.   Search for all .py files in subdirectories too.
+-n (--nobackup) No backup. Does not make a ".bak" file before reindenting.
+-v (--verbose)  Verbose.   Print informative msgs; else no output.
+   (--newline)  Newline.   Specify the newline character to use (CRLF, LF).
+                           Default is the same as the original file.
+-h (--help)     Help.      Print this usage information and exit.
+
+Change Python (.py) files to use 4-space indents and no hard tab characters.
+Also trim excess spaces and tabs from ends of lines, and remove empty lines
+at the end of files.  Also ensure the last line ends with a newline.
+
+If no paths are given on the command line, reindent operates as a filter,
+reading a single source file from standard input and writing the transformed
+source to standard output.  In this case, the -d, -r and -v flags are
+ignored.
+
+You can pass one or more file and/or directory paths.  When a directory
+path, all .py files within the directory will be examined, and, if the -r
+option is given, likewise recursively for subdirectories.
+
+If output is not to standard output, reindent overwrites files in place,
+renaming the originals with a .bak extension.  If it finds nothing to
+change, the file is left alone.  If reindent does change a file, the changed
+file is a fixed-point for future runs (i.e., running reindent on the
+resulting .py file won't change it again).
+
+The hard part of reindenting is figuring out what to do with comment
+lines.  So long as the input files get a clean bill of health from
+tabnanny.py, reindent should do a good job.
+
+The backup file is a copy of the one that is being reindented. The ".bak"
+file is generated with shutil.copy(), but some corner cases regarding
+user/group and permissions could leave the backup file more readable than
+you'd prefer. You can always use the --nobackup option to prevent this.
+"""
+
+__version__ = "1"
+
+import tokenize
+import os
+import shutil
 import sys
 
-in_path  = sys.argv[1]
+verbose = False
-out_path = sys.argv[2]
+recurse = False
+dryrun = False
+makebackup = True
+# A specified newline to be used in the output (set by --newline option)
+spec_newline = None
 
-with open(in_path, 'r', encoding='utf-8') as f:
-    lines = f.readlines()
 
-fixed = []
+def usage(msg=None):
-for line in lines:
+    if msg is None:
-    # Tabs → 4 Spaces, Strip trailing Spaces
+        msg = __doc__
-    new = line.expandtabs(4).rstrip()
+    print(msg, file=sys.stderr)
-    fixed.append(new + '\n')
 
-with open(out_path, 'w', encoding='utf-8') as f:
+
-    f.writelines(fixed)
+def errprint(*args):
-print(f"Neu eingerückt und gespeichert: {out_path}")
+    sys.stderr.write(" ".join(str(arg) for arg in args))
+    sys.stderr.write("\n")
+
+def main():
+    import getopt
+    global verbose, recurse, dryrun, makebackup, spec_newline
+    try:
+        opts, args = getopt.getopt(sys.argv[1:], "drnvh",
+            ["dryrun", "recurse", "nobackup", "verbose", "newline=", "help"])
+    except getopt.error as msg:
+        usage(msg)
+        return
+    for o, a in opts:
+        if o in ('-d', '--dryrun'):
+            dryrun = True
+        elif o in ('-r', '--recurse'):
+            recurse = True
+        elif o in ('-n', '--nobackup'):
+            makebackup = False
+        elif o in ('-v', '--verbose'):
+            verbose = True
+        elif o in ('--newline',):
+            if not a.upper() in ('CRLF', 'LF'):
+                usage()
+                return
+            spec_newline = dict(CRLF='\r\n', LF='\n')[a.upper()]
+        elif o in ('-h', '--help'):
+            usage()
+            return
+    if not args:
+        r = Reindenter(sys.stdin)
+        r.run()
+        r.write(sys.stdout)
+        return
+    for arg in args:
+        check(arg)
+
+
+def check(file):
+    if os.path.isdir(file) and not os.path.islink(file):
+        if verbose:
+            print("listing directory", file)
+        names = os.listdir(file)
+        for name in names:
+            fullname = os.path.join(file, name)
+            if ((recurse and os.path.isdir(fullname) and
+                 not os.path.islink(fullname) and
+                 not os.path.split(fullname)[1].startswith("."))
+                or name.lower().endswith(".py")):
+                check(fullname)
+        return
+
+    if verbose:
+        print("checking", file, "...", end=' ')
+    with open(file, 'rb') as f:
+        try:
+            encoding, _ = tokenize.detect_encoding(f.readline)
+        except SyntaxError as se:
+            errprint("%s: SyntaxError: %s" % (file, str(se)))
+            return
+    try:
+        with open(file, encoding=encoding) as f:
+            r = Reindenter(f)
+    except IOError as msg:
+        errprint("%s: I/O Error: %s" % (file, str(msg)))
+        return
+
+    newline = spec_newline if spec_newline else r.newlines
+    if isinstance(newline, tuple):
+        errprint("%s: mixed newlines detected; cannot continue without --newline" % file)
+        return
+
+    if r.run():
+        if verbose:
+            print("changed.")
+            if dryrun:
+                print("But this is a dry run, so leaving it alone.")
+        if not dryrun:
+            bak = file + ".bak"
+            if makebackup:
+                shutil.copyfile(file, bak)
+                if verbose:
+                    print("backed up", file, "to", bak)
+            with open(file, "w", encoding=encoding, newline=newline) as f:
+                r.write(f)
+            if verbose:
+                print("wrote new", file)
+        return True
+    else:
+        if verbose:
+            print("unchanged.")
+        return False
+
+
+def _rstrip(line, JUNK='\n \t'):
+    """Return line stripped of trailing spaces, tabs, newlines.
+
+    Note that line.rstrip() instead also strips sundry control characters,
+    but at least one known Emacs user expects to keep junk like that, not
+    mentioning Barry by name or anything <wink>.
+    """
+
+    i = len(line)
+    while i > 0 and line[i - 1] in JUNK:
+        i -= 1
+    return line[:i]
+
+
+class Reindenter:
+
+    def __init__(self, f):
+        self.find_stmt = 1  # next token begins a fresh stmt?
+        self.level = 0      # current indent level
+
+        # Raw file lines.
+        self.raw = f.readlines()
+
+        # File lines, rstripped & tab-expanded.  Dummy at start is so
+        # that we can use tokenize's 1-based line numbering easily.
+        # Note that a line is all-blank iff it's "\n".
+        self.lines = [_rstrip(line).expandtabs() + "\n"
+                      for line in self.raw]
+        self.lines.insert(0, None)
+        self.index = 1  # index into self.lines of next line
+
+        # List of (lineno, indentlevel) pairs, one for each stmt and
+        # comment line.  indentlevel is -1 for comment lines, as a
+        # signal that tokenize doesn't know what to do about them;
+        # indeed, they're our headache!
+        self.stats = []
+
+        # Save the newlines found in the file so they can be used to
+        #  create output without mutating the newlines.
+        self.newlines = f.newlines
+
+    def run(self):
+        tokens = tokenize.generate_tokens(self.getline)
+        for _token in tokens:
+            self.tokeneater(*_token)
+        # Remove trailing empty lines.
+        lines = self.lines
+        while lines and lines[-1] == "\n":
+            lines.pop()
+        # Sentinel.
+        stats = self.stats
+        stats.append((len(lines), 0))
+        # Map count of leading spaces to # we want.
+        have2want = {}
+        # Program after transformation.
+        after = self.after = []
+        # Copy over initial empty lines -- there's nothing to do until
+        # we see a line with *something* on it.
+        i = stats[0][0]
+        after.extend(lines[1:i])
+        for i in range(len(stats) - 1):
+            thisstmt, thislevel = stats[i]
+            nextstmt = stats[i + 1][0]
+            have = getlspace(lines[thisstmt])
+            want = thislevel * 4
+            if want < 0:
+                # A comment line.
+                if have:
+                    # An indented comment line.  If we saw the same
+                    # indentation before, reuse what it most recently
+                    # mapped to.
+                    want = have2want.get(have, -1)
+                    if want < 0:
+                        # Then it probably belongs to the next real stmt.
+                        for j in range(i + 1, len(stats) - 1):
+                            jline, jlevel = stats[j]
+                            if jlevel >= 0:
+                                if have == getlspace(lines[jline]):
+                                    want = jlevel * 4
+                                break
+                    if want < 0:           # Maybe it's a hanging
+                                           # comment like this one,
+                        # in which case we should shift it like its base
+                        # line got shifted.
+                        for j in range(i - 1, -1, -1):
+                            jline, jlevel = stats[j]
+                            if jlevel >= 0:
+                                want = have + (getlspace(after[jline - 1]) -
+                                               getlspace(lines[jline]))
+                                break
+                    if want < 0:
+                        # Still no luck -- leave it alone.
+                        want = have
+                else:
+                    want = 0
+            assert want >= 0
+            have2want[have] = want
+            diff = want - have
+            if diff == 0 or have == 0:
+                after.extend(lines[thisstmt:nextstmt])
+            else:
+                for line in lines[thisstmt:nextstmt]:
+                    if diff > 0:
+                        if line == "\n":
+                            after.append(line)
+                        else:
+                            after.append(" " * diff + line)
+                    else:
+                        remove = min(getlspace(line), -diff)
+                        after.append(line[remove:])
+        return self.raw != self.after
+
+    def write(self, f):
+        f.writelines(self.after)
+
+    # Line-getter for tokenize.
+    def getline(self):
+        if self.index >= len(self.lines):
+            line = ""
+        else:
+            line = self.lines[self.index]
+            self.index += 1
+        return line
+
+    # Line-eater for tokenize.
+    def tokeneater(self, type, token, slinecol, end, line,
+                   INDENT=tokenize.INDENT,
+                   DEDENT=tokenize.DEDENT,
+                   NEWLINE=tokenize.NEWLINE,
+                   COMMENT=tokenize.COMMENT,
+                   NL=tokenize.NL):
+
+        if type == NEWLINE:
+            # A program statement, or ENDMARKER, will eventually follow,
+            # after some (possibly empty) run of tokens of the form
+            #     (NL | COMMENT)* (INDENT | DEDENT+)?
+            self.find_stmt = 1
+
+        elif type == INDENT:
+            self.find_stmt = 1
+            self.level += 1
+
+        elif type == DEDENT:
+            self.find_stmt = 1
+            self.level -= 1
+
+        elif type == COMMENT:
+            if self.find_stmt:
+                self.stats.append((slinecol[0], -1))
+                # but we're still looking for a new stmt, so leave
+                # find_stmt alone
+
+        elif type == NL:
+            pass
+
+        elif self.find_stmt:
+            # This is the first "real token" following a NEWLINE, so it
+            # must be the first token of the next program statement, or an
+            # ENDMARKER.
+            self.find_stmt = 0
+            if line:   # not endmarker
+                self.stats.append((slinecol[0], self.level))
+
+
+# Count number of leading blanks.
+def getlspace(line):
+    i, n = 0, len(line)
+    while i < n and line[i] == " ":
+        i += 1
+    return i
+
+
+if __name__ == '__main__':
+    main()