[Python-Dev] Single-file Python executables (was: Computed Goto dispatch for Python 2)

[Steve Dower]

Donald Stufft wrote:
> On May 28, 2015 at 11:30:37 AM, Steve Dower (steve.dower at microsoft.com) wrote:
>> Donald Stufft wrote:
>> > Well Python 3.4.3 binary is 4kb for me, so you'd have that + your
>> > 1KB Python script + whatever
>> other pieces you need.
>>
>> For contrast, here are the things you need on Windows to be able to
>> get to an interactive prompt (I don't know how other platforms get this down
>> to 4KB...):
>>
>> * python.exe (or some equivalent launcher) 39KB
>> * python35.dll 3,788KB
>> * vcruntime140.dll 87KB (the rest of the CRT is about 1MB, but is not
>> redistributable so doesn't count here)
>> * 26 files in Lib 343KB
>>
>> This gets you to ">>>", and basically everything after that is going to fail
> for some reason.
>> That's an unavoidable 4,257KB.
>>
>> The rest of the stdlib adds another ~16MB once you exclude the test
>> suite, so a fully functioning Python is not cheap. (Using compressed
>> .pyc's in a zip file can make a big difference here though, assuming
>> you're willing to trade CPU for HDD.)
>>
>> Cheers,
>> Steve
>>
>>
> 
> You don’t need a "fully functioning Python" for a single file binary, you only
> need enough to actually run your application. For example, if you're making an
> application that can download files over HTTP, you don't need to include parts
> of the stdlib like xmlrpc, pickle, shelve, marshall, sqlite, csv, email,
> mailcap, mailbox, imaplib, nntplib, etc.
> 
> Of course deciding which pieces you include in the zip file you're appending to
> the end of Python is up to whatever tool builds this executable which doesn't
> need to be part of Python itself. If Python itself gained the ability to operate
> in that manner than third party tools could handle trying to do the
> optimizations where it only includes the things it actually needs in the stdlib
> and excludes things it doesn't. The key thing here is that since you're doing a
> single file binary, you don't need to have a Python which is suitable to execute
> random Python code, you only need one that is suitable to execute this
> particular code so you can specialize what that includes.

Agreed, but the minimally functioning Python is barely under 5MB. That will be considered bloated and won't help us compete with Go, so we should find a better way to fix Python application distribution and stop getting so hung up on putting everything into a single executable file.

Cheers,
Steve