From a2359e0554e5fb68307b58d75920289f0fcda307 Mon Sep 17 00:00:00 2001 From: guido Date: Thu, 1 Feb 2007 16:58:42 +0100 Subject: [PATCH] [svn r37752] Added some more code examples. --HG-- branch : trunk --- py/doc/path.txt | 96 +++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 85 insertions(+), 11 deletions(-) diff --git a/py/doc/path.txt b/py/doc/path.txt index 3b809abb8..25c8fed5b 100644 --- a/py/doc/path.txt +++ b/py/doc/path.txt @@ -8,7 +8,8 @@ py.path The 'py' lib provides a uniform high-level api to deal with filesystems and filesystem-like interfaces: :api:`py.path`. It aims to offer a central object to fs-like object trees (reading from and writing to files, adding -files/directories, examining the types and structure, etc.). +files/directories, examining the types and structure, etc.), and out-of-the-box +provides a number of implementations of this API. Path implementations provided by :api:`py.path` =============================================== @@ -34,6 +35,9 @@ a :api:`py.path.local` object for us (which wraps a directory):: True >>> foopath.read() 'bar' + >>> foofile = foopath.open() # return a 'real' file object + >>> foofile.read(1) + 'b' :api:`py.path.svnurl` and :api:`py.path.svnwc` ---------------------------------------------- @@ -74,32 +78,103 @@ for many use cases and allowing to transparently switch the path object within an application (e.g. from "local" to "svnwc"). The common set includes functions such as `path.read()` to read all data from a file, `path.write()` to write data, `path.listdir()` to get a list -of directory entries, and `path.check()` to check if a node exists +of directory entries, `path.check()` to check if a node exists and is of a particular type, `path.join()` to get to a (grand)child, `path.visit()` to recursively walk through a node's -children, etc. Only things that are not common on all filesystems, such -as handling metadata (e.g. the subversion "properties") require +children, etc. Only things that are not common on 'normal' filesystems (yet), +such as handling metadata (e.g. the Subversion "properties") require using specific APIs. Examples --------------------------------- +A quick 'cookbook' of small examples that will be useful 'in real life', +which also presents parts of the 'common' API, and shows some non-common +methods: + Searching `.txt` files +++++++++++++++++++++++++++++++++++++ -XXX example +Search for a particular string inside all files with a .txt extension in a +specific directory. +:: -Joining and checking path types -+++++++++++++++++++++++++++++++++++++ + >>> dirpath = temppath.ensure('testdir', dir=True) + >>> dirpath.join('textfile1.txt').write('foo bar baz') + >>> dirpath.join('textfile2.txt').write('frob bar spam eggs') + >>> subdir = dirpath.ensure('subdir', dir=True) + >>> subdir.join('textfile1.txt').write('foo baz') + >>> subdir.join('textfile2.txt').write('spam eggs spam foo bar spam') + >>> results = [] + >>> for fpath in dirpath.visit('*.txt'): + ... if 'bar' in fpath.read(): + ... results.append(fpath.relto(dirpath)) + >>> results + ['textfile1.txt', 'textfile2.txt', 'subdir/textfile2.txt'] -XXX example +Joining path types +++++++++++++++++++++ -setting svn-properties +This example shows the :api:`py.path` features to deal with actual paths +(strings). Note that the filesystem is never touched, all operations are +performed on a string level (so the paths don't have to exist, either):: + + >>> p1 = py.path.local('/foo/bar') + >>> p2 = p1.join('baz/qux') + >>> p2.strpath + '/foo/bar/baz/qux' + >>> p2.relto(p1) + 'baz/qux' + >>> p3 = p1 / 'baz/qux' # the / operator allows joining, too + >>> p2 == p3 + True + +This should be possible on every implementation of :api:`py.path`, so +regardless of whether the implementation wraps a UNIX filesystem, a Windows +one, or a database or object tree, these functions should be available (each +with their own notion of path seperators and dealing with conversions, etc.). + +Checking path types ++++++++++++++++++++++ + +Now we will show a bit about the powerful 'check()' method on paths, which +allows you to check whether a file exists, what type it is, etc.:: + + >>> file1 = temppath.join('file1') + >>> file1.check() # does it exist? + False + >>> file1 = file1.ensure(file=True) # 'touch' the file + >>> file1.check() + True + >>> file1.check(dir=True) # is it a dir? + False + >>> file1.check(file=True) # or a file? + True + >>> file1.check(ext='.txt') # check the extension + False + >>> textfile = temppath.ensure('text.txt', file=True) + >>> textfile.check(ext='.txt') + True + >>> file1.check(basename='file1') # we can use all the path's properties here + True + +Setting svn-properties +++++++++++++++++++++++++++++++++++++++ -XXX example +As an example of 'uncommon' methods, we'll show how to read and write +properties in an :api:`py.path.svnwc` instance:: + >>> wc.propget('foo') + '' + >>> wc.propset('foo', 'bar') + >>> wc.propget('foo') + 'bar' + >>> len(wc.status().prop_modified) # our own props + 1 + >>> msg = wc.revert() # roll back our changes + >>> len(wc.status().prop_modified) + 0 XXX more examples (look at API) +++++++++++++++++++++++++++++++++++++++ @@ -117,7 +192,6 @@ is a bit fragile across versions and locales XXX note more here - Future plans ============