1 #! /usr/bin/env python3 2 3 """cleanfuture [-d][-r][-v] path ... 4 5 -d Dry run. Analyze, but don't make any changes to, files. 6 -r Recurse. Search for all .py files in subdirectories too. 7 -v Verbose. Print informative msgs. 8 9 Search Python (.py) files for future statements, and remove the features 10 from such statements that are already mandatory in the version of Python 11 you're using. 12 13 Pass one or more file and/or directory paths. When a directory path, all 14 .py files within the directory will be examined, and, if the -r option is 15 given, likewise recursively for subdirectories. 16 17 Overwrites files in place, renaming the originals with a .bak extension. If 18 cleanfuture finds nothing to change, the file is left alone. If cleanfuture 19 does change a file, the changed file is a fixed-point (i.e., running 20 cleanfuture on the resulting .py file won't change it again, at least not 21 until you try it again with a later Python release). 22 23 Limitations: You can do these things, but this tool won't help you then: 24 25 + A future statement cannot be mixed with any other statement on the same 26 physical line (separated by semicolon). 27 28 + A future statement cannot contain an "as" clause. 29 30 Example: Assuming you're using Python 2.2, if a file containing 31 32 from __future__ import nested_scopes, generators 33 34 is analyzed by cleanfuture, the line is rewritten to 35 36 from __future__ import generators 37 38 because nested_scopes is no longer optional in 2.2 but generators is. 39 """ 40 41 import __future__ 42 import tokenize 43 import os 44 import sys 45 46 dryrun = 0 47 recurse = 0 48 verbose = 0 49 50 def errprint(*args): 51 strings = map(str, args) 52 msg = ' '.join(strings) 53 if msg[-1:] != '\n': 54 msg += '\n' 55 sys.stderr.write(msg) 56 57 def main(): 58 import getopt 59 global verbose, recurse, dryrun 60 try: 61 opts, args = getopt.getopt(sys.argv[1:], "drv") 62 except getopt.error as msg: 63 errprint(msg) 64 return 65 for o, a in opts: 66 if o == '-d': 67 dryrun += 1 68 elif o == '-r': 69 recurse += 1 70 elif o == '-v': 71 verbose += 1 72 if not args: 73 errprint("Usage:", __doc__) 74 return 75 for arg in args: 76 check(arg) 77 78 def check(file): 79 if os.path.isdir(file) and not os.path.islink(file): 80 if verbose: 81 print("listing directory", file) 82 names = os.listdir(file) 83 for name in names: 84 fullname = os.path.join(file, name) 85 if ((recurse and os.path.isdir(fullname) and 86 not os.path.islink(fullname)) 87 or name.lower().endswith(".py")): 88 check(fullname) 89 return 90 91 if verbose: 92 print("checking", file, "...", end=' ') 93 try: 94 f = open(file) 95 except IOError as msg: 96 errprint("%r: I/O Error: %s" % (file, str(msg))) 97 return 98 99 ff = FutureFinder(f, file) 100 changed = ff.run() 101 if changed: 102 ff.gettherest() 103 f.close() 104 if changed: 105 if verbose: 106 print("changed.") 107 if dryrun: 108 print("But this is a dry run, so leaving it alone.") 109 for s, e, line in changed: 110 print("%r lines %d-%d" % (file, s+1, e+1)) 111 for i in range(s, e+1): 112 print(ff.lines[i], end=' ') 113 if line is None: 114 print("-- deleted") 115 else: 116 print("-- change to:") 117 print(line, end=' ') 118 if not dryrun: 119 bak = file + ".bak" 120 if os.path.exists(bak): 121 os.remove(bak) 122 os.rename(file, bak) 123 if verbose: 124 print("renamed", file, "to", bak) 125 g = open(file, "w") 126 ff.write(g) 127 g.close() 128 if verbose: 129 print("wrote new", file) 130 else: 131 if verbose: 132 print("unchanged.") 133 134 class FutureFinder: 135 136 def __init__(self, f, fname): 137 self.f = f 138 self.fname = fname 139 self.ateof = 0 140 self.lines = [] # raw file lines 141 142 # List of (start_index, end_index, new_line) triples. 143 self.changed = [] 144 145 # Line-getter for tokenize. 146 def getline(self): 147 if self.ateof: 148 return "" 149 line = self.f.readline() 150 if line == "": 151 self.ateof = 1 152 else: 153 self.lines.append(line) 154 return line 155 156 def run(self): 157 STRING = tokenize.STRING 158 NL = tokenize.NL 159 NEWLINE = tokenize.NEWLINE 160 COMMENT = tokenize.COMMENT 161 NAME = tokenize.NAME 162 OP = tokenize.OP 163 164 changed = self.changed 165 get = tokenize.generate_tokens(self.getline).__next__ 166 type, token, (srow, scol), (erow, ecol), line = get() 167 168 # Chew up initial comments and blank lines (if any). 169 while type in (COMMENT, NL, NEWLINE): 170 type, token, (srow, scol), (erow, ecol), line = get() 171 172 # Chew up docstring (if any -- and it may be implicitly catenated!). 173 while type is STRING: 174 type, token, (srow, scol), (erow, ecol), line = get() 175 176 # Analyze the future stmts. 177 while 1: 178 # Chew up comments and blank lines (if any). 179 while type in (COMMENT, NL, NEWLINE): 180 type, token, (srow, scol), (erow, ecol), line = get() 181 182 if not (type is NAME and token == "from"): 183 break 184 startline = srow - 1 # tokenize is one-based 185 type, token, (srow, scol), (erow, ecol), line = get() 186 187 if not (type is NAME and token == "__future__"): 188 break 189 type, token, (srow, scol), (erow, ecol), line = get() 190 191 if not (type is NAME and token == "import"): 192 break 193 type, token, (srow, scol), (erow, ecol), line = get() 194 195 # Get the list of features. 196 features = [] 197 while type is NAME: 198 features.append(token) 199 type, token, (srow, scol), (erow, ecol), line = get() 200 201 if not (type is OP and token == ','): 202 break 203 type, token, (srow, scol), (erow, ecol), line = get() 204 205 # A trailing comment? 206 comment = None 207 if type is COMMENT: 208 comment = token 209 type, token, (srow, scol), (erow, ecol), line = get() 210 211 if type is not NEWLINE: 212 errprint("Skipping file %r; can't parse line %d:\n%s" % 213 (self.fname, srow, line)) 214 return [] 215 216 endline = srow - 1 217 218 # Check for obsolete features. 219 okfeatures = [] 220 for f in features: 221 object = getattr(__future__, f, None) 222 if object is None: 223 # A feature we don't know about yet -- leave it in. 224 # They'll get a compile-time error when they compile 225 # this program, but that's not our job to sort out. 226 okfeatures.append(f) 227 else: 228 released = object.getMandatoryRelease() 229 if released is None or released <= sys.version_info: 230 # Withdrawn or obsolete. 231 pass 232 else: 233 okfeatures.append(f) 234 235 # Rewrite the line if at least one future-feature is obsolete. 236 if len(okfeatures) < len(features): 237 if len(okfeatures) == 0: 238 line = None 239 else: 240 line = "from __future__ import " 241 line += ', '.join(okfeatures) 242 if comment is not None: 243 line += ' ' + comment 244 line += '\n' 245 changed.append((startline, endline, line)) 246 247 # Loop back for more future statements. 248 249 return changed 250 251 def gettherest(self): 252 if self.ateof: 253 self.therest = '' 254 else: 255 self.therest = self.f.read() 256 257 def write(self, f): 258 changed = self.changed 259 assert changed 260 # Prevent calling this again. 261 self.changed = [] 262 # Apply changes in reverse order. 263 changed.reverse() 264 for s, e, line in changed: 265 if line is None: 266 # pure deletion 267 del self.lines[s:e+1] 268 else: 269 self.lines[s:e+1] = [line] 270 f.writelines(self.lines) 271 # Copy over the remainder of the file. 272 if self.therest: 273 f.write(self.therest) 274 275 if __name__ == '__main__': 276 main() 277
