* string.py: added rindex(), rfind(); changed index() to interpret

negative start indices starting from the right.
* ftplib.py: debug() -> set_debuglevel(); change demo to use __init__().
* os.py: added execl, execlp, and execvp.
* lambda.py: removed (now that we have built-in map, reduce, bagof, lambda)
* test_b{1,2}.py, testall.out: added tests for bagof, lambda, map, reduce
* commands.py: use os, not posix
* test_grammar.py: make it easy to disable non-portable int overflow tests
* dis.py: don't abuse range()

Lib/os.py

@@ -38,3 +38,33 @@ except ImportError:
 	import macpath
 	path = macpath
 	del macpath
+
+def execl(file, *args):
+	execv(file, args)
+
+def execle(file, *args):
+	env = args[-1]
+	execve(file, args[:-1], env)
+
+def execlp(file, *args):
+	execvp(file, args)
+
+def execvp(file, args):
+	if '/' in file:
+		execv(file, args)
+		return
+	ENOENT = 2
+	if environ.has_key('PATH'):
+		import string
+		PATH = string.splitfields(environ['PATH'], ':')
+	else:
+		PATH = ['', '/bin', '/usr/bin']
+	exc, arg = (ENOENT, 'No such file or directory')
+	for dir in PATH:
+		fullname = path.join(dir, file)
+		try:
+			execv(fullname, args)
+		except error, (errno, msg):
+			if errno != ENOENT:
+				exc, arg = error, (errno, msg)
+	raise exc, arg