- it's possible to convert every Perl programm into an
equivalent programm written in Python since both languages are
turing-complete (at least they should ;-)
- this is nearly impossible since Perl and Python have a very
differt style of expressing things.
What 'bridgekeeper' does
'bridgekeeper' helps converting Perl code to Python source. The
quality of the output Python source depents on the quality of the
If there are constructs within the Perl code which are not possible
in Python, you will get warnings. Eg. when using a name for both a
hash and a scalar within the same scope (%foo, $foo).
'bridgekeeper' consists of
- a Perl compiler back-end emitting Python-like source and
- a runtime Python package which tries to emulate some perl build-in
The name was inspired be the bridgekeeper-scene in Monty Pythons
'Search for the Holy Grail'.
- Already converts a lot of Perl code-constructs into Python source:
loops, special variables, function calls, lists, hashes, methods,
- Whenever there is no equivalent Python function for a Perl
function, the function is emulated using the included Python
- Warns about variables with same name but different type within a
scope, eg. when using a name for both a hash and a scalar (%foo,
$foo). This included scalars, hashes, lists, arrays and
- Warns about mixing variables with same name but different Perl
scoping within a Python scope, eg. using (global) $foo and my $foo
in one scope.
- Strips statements like 'my ($foo, %bar);'; this is: my and local
declarations without assignment.
- Special variables are renamed to their equivalent within the
included Python library.
- 'here-documents' are supported.
- Does not yet support 'use', 'BEGIN', 'END', etc. This is due how Perl
handles these expressions: they get executed while parsing. See
the Tutorial for solving this problem.
- Does not handle 'bless', 'packages', etc.
- References may or may not be resolved correctly.
- Does not convert things like 'my ($self, arg1, arg2) = @_;' into a
pythonic argument-lists. (Hey, this would be a great
- In some rare cases Perl functions are converted to the
nearly-equivalent Python function instead of using a emulated
function. This is done for functions which return a value which is
probly not often used.
- The Python libary included contains all required functions, while
many of them are not yet implemented.
- Formats are not supported anyhow. (But I already have an idea how
this could be done: use a class perl.Format thatfore.) This also
includes the function 'write'.
- Separate prototype declarations are not supported, whereas
prototypes at function definitions are taken over (as
- Prefix/postfix operator are not resolved.
- Esoteric execution orders are not supported (see
- The Python libary included is not thread-save -- and probably will
never become thread-save.
- A lot more :-)
- For converting Perl to Python you need a running Perl
installations. I tried Perl 5.6.0 on a Linux box, but every other
Perl5 should work, too.
- For running the converted source you need to at least Python 2.2.
- The compiler back-end 'B::Bridgekepper.pm' is based on
'B::Deparse.pm' written by Stephen McCamant.
- The runtime Python package was inspired by 'pyperlish' written by
The bad news: Unfortunatly, there is no way to
'try out' bridgekeeper. It's simply not available for puchasing.
The good news:But we can offer you consultancy for
this conversion (where we will use bridgekeeper as a mighty tool). If
you are interested in hireing me for a project,
please drop me a note.
Another good news:We plan to offer a conversion
service, much like we to for decompyle. But
this will still take some time for settling down the code.