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- THE FREEZE SCRIPT
- =================
-
-
- What is Freeze?
- ---------------
-
- Freeze make it possible to ship arbitrary Python programs to people
- who don't have Python. The shipped file (called a "frozen" version of
- your Python program) is an executable, so this only works if your
- platform is compatible with that on the receiving end (this is usually
- a matter of having the same major operating system revision and CPU
- type).
-
- The shipped file contains a Python interpreter and large portions of
- the Python run-time. Some measures have been taken to avoid linking
- unneeded modules, but the resulting binary is usually not small.
-
- The Python source code of your program (and of the library modules
- written in Python that it uses) is not included in the binary --
- instead, the compiled byte-code (the instruction stream used
- internally by the interpreter) is incorporated. This gives some
- protection of your Python source code, though not much -- a
- disassembler for Python byte-code is available in the standard Python
- library. At least someone running "strings" on your binary won't see
- the source.
-
-
- How does Freeze know which modules to include?
- ----------------------------------------------
-
- Freeze uses a pretty simple-minded algorithm to find the modules that
- your program uses: given a file containing Python source code, it
- scans for lines beginning with the word "import" or "from" (possibly
- preceded by whitespace) and then it knows where to find the module
- name(s) in those lines. It then recursively scans the source for
- those modules (if found, and not already processed) in the same way.
-
- Freeze will not see import statements hidden behind another statement,
- like this:
-
- if some_test: import M # M not seen
-
- or like this:
-
- import A; import B; import C # B and C not seen
-
- nor will it see import statements constructed using string
- operations and passed to 'exec', like this:
-
- exec "import %s" % "M" # M not seen
-
- On the other hand, Freeze will think you are importing a module even
- if the import statement it sees will never be executed, like this:
-
- if 0:
- import M # M is seen
-
- One tricky issue: Freeze assumes that the Python interpreter and
- environment you're using to run Freeze is the same one that would be
- used to run your program, which should also be the same whose sources
- and installed files you will learn about in the next section. In
- particular, your PYTHONPATH setting should be the same as for running
- your program locally. (Tip: if the program doesn't run when you type
- "python hello.py" there's little chance of getting the frozen version
- to run.)
-
-
- How do I use Freeze?
- --------------------
-
- Normally, you should be able to use it as follows:
-
- python freeze.py hello.py
-
- where hello.py is your program and freeze.py is the main file of
- Freeze (in actuality, you'll probably specify an absolute pathname
- such as /usr/joe/python/Tools/freeze/freeze.py).
-
- (With Python 1.4, freeze is much more likely to work "out of the box"
- than before, provided Python has been installed properly.)
-
-
- What do I do next?
- ------------------
-
- Freeze creates three files: frozen.c, config.c and Makefile. To
- produce the frozen version of your program, you can simply type
- "make". This should produce a binary file. If the filename argument
- to Freeze was "hello.py", the binary will be called "hello".
-
- Note: you can use the -o option to freeze to specify an alternative
- directory where these files are created. This makes it easier to
- clean up after you've shipped the frozen binary.
-
-
- Troubleshooting
- ---------------
-
- If you have trouble using Freeze for a large program, it's probably
- best to start playing with a really simple program first (like the file
- hello.py). If you can't get that to work there's something
- fundamentally wrong -- perhaps you haven't installed Python. To do a
- proper install, you should do "make install" in the Python root
- directory.
-
-
- --Guido van Rossum (home page: http://www.python.org/~guido/)
-