[Python编程(第4版)].(Programming.Python.4th.Edition).Mark.Lutz.文字版

if name == 'main':
listonly = input('List only?') == 'y'
visitor = ReplaceVisitor(sys.argv[2], sys.argv[3], listonly)
if listonly or input('Proceed with changes?') == 'y':
visitor.run(startDir=sys.argv[1])
action = 'Changed' if not listonly else 'Found'
print('Visited %d files' % visitor.fcount)
print(action, '%d files:' % len(visitor.changed))
for fname in visitor.changed: print(fname)

To run this script over a directory tree, run the following sort of command line with
appropriate “from” and “to” strings. On my shockingly underpowered netbook ma-
chine, doing this on a 1429-file tree and changing 101 files along the way takes roughly
three seconds of real clock time when the system isn’t particularly busy.

C:\...\PP4E\Tools> visitor_replace.py C:\temp\PP3E\Examples PP3E PP4E

List only?y

Visited 1429 files

Found 101 files:

C:\temp\PP3E\Examples\README-root.txt

C:\temp\PP3E\Examples\PP3E\echoEnvironment.pyw

C:\temp\PP3E\Examples\PP3E\Launcher.py

...more matching filenames omitted...

C:\...\PP4E\Tools> visitor_replace.py C:\temp\PP3E\Examples PP3E PP4E

List only?n

Proceed with changes?y

Visited 1429 files

Changed 101 files:

C:\temp\PP3E\Examples\README-root.txt

C:\temp\PP3E\Examples\PP3E\echoEnvironment.pyw

C:\temp\PP3E\Examples\PP3E\Launcher.py

...more changed filenames omitted...

C:\...\PP4E\Tools> visitor_replace.py C:\temp\PP3E\Examples PP3E PP4E

List only?n

Proceed with changes?y

Visited 1429 files

Changed 0 files:

Naturally, we can also check our work by running the visitor script (and
SearchVisitor superclass):

C:\...\PP4E\Tools> visitor.py 2 C:\temp\PP3E\Examples PP3E

Found in 0 files, visited 1429

C:\...\PP4E\Tools> visitor.py 2 C:\temp\PP3E\Examples PP4E

C:\temp\PP3E\Examples\README-root.txt has PP4E

C:\temp\PP3E\Examples\PP3E\echoEnvironment.pyw has PP4E

C:\temp\PP3E\Examples\PP3E\Launcher.py has PP4E

...more matching filenames omitted...

Found in 101 files, visited 1429

Visitor: Walking Directories “++” | 337