New tool for normalizing indentation of .py files.

Tools/scripts/reindent.py

+#! /usr/bin/env python
+
+# Released to the public domain, by Tim Peters, 03 October 2000.
+
+"""reindent [-d][-r][-v] path ...
+
+-d  Dry run.  Analyze, but don't make any changes to, files.
+-r  Recurse.  Search for all .py files in subdirectories too.
+-v  Verbose.  Print informative msgs; else no output.
+
+Change Python (.py) files to use 4-space indents and no hard tab characters.
+Also trim excess whitespace from ends of lines, and empty lines at the ends
+of files.  Ensure the last line ends with a newline.
+
+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.
+
+Overwrites files in place, renaming the originals with a .bak extension.
+If reindent finds nothing to change, the file is left alone.  If reindent
+does change a file, the changed file is a fixed-point for reindent (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.
+"""
+
+__version__ = "1"
+
+import tokenize
+import os
+import sys
+
+verbose = 0
+recurse = 0
+dryrun  = 0
+
+def errprint(*args):
+    sep = ""
+    for arg in args:
+        sys.stderr.write(sep + str(arg))
+        sep = " "
+    sys.stderr.write("\n")
+
+def main():
+    import getopt
+    global verbose, recurse, dryrun
+    try:
+        opts, args = getopt.getopt(sys.argv[1:], "drv")
+    except getopt.error, msg:
+        errprint(msg)
+        return
+    for o, a in opts:
+        if o == '-d':
+            dryrun += 1
+        elif o == '-r':
+            recurse += 1
+        elif o == '-v':
+            verbose += 1
+    if not args:
+        errprint("Usage:", __doc__)
+        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))
+                or name.lower().endswith(".py")):
+                check(fullname)
+        return
+
+    if verbose:
+        print "checking", file, "...",
+    try:
+        f = open(file)
+    except IOError, msg:
+        errprint("%s: I/O Error: %s" % (file, str(msg)))
+        return
+
+    r = Reindenter(f)
+    f.close()
+    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 os.path.exists(bak):
+                os.remove(bak)
+            os.rename(file, bak)
+            if verbose:
+                print "renamed", file, "to", bak
+            f = open(file, "w")
+            r.write(f)
+            f.close()
+            if verbose:
+                print "wrote new", file
+    else:
+        if verbose:
+            print "unchanged."
+
+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 = [line.rstrip().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 = []
+
+    def run(self):
+        tokenize.tokenize(self.getline, self.tokeneater)
+        # 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 = []
+        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 xrange(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 xrange(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, (sline, scol), 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((sline, -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((sline, 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()