In [13]:

!touch test.html

In [30]:

import webbrowser
webbrowser.get('Safari').open('test.html')

Out[30]:

True

Call LSCopyDefaultApplicationURLForURL to discover the location of the application associated with a given url.

Use ctypes to call apple APIs.

In [2]:

import ctypes
from ctypes import c_void_p, Structure, POINTER

kCFStringEncodingUTF8 = 0x08000100

CoreFoundation = ctypes.cdll.LoadLibrary(ctypes.util.find_library('CoreFoundation'))
LaunchServices = ctypes.cdll.LoadLibrary(ctypes.util.find_library('LaunchServices'))

# create CFURL from bytes
CFURLCreateWithBytes = CoreFoundation.CFURLCreateWithBytes
CFURLCreateWithBytes.restype = c_void_p
CFURLCreateWithBytes.argtypes = [c_void_p, ctypes.c_char_p, ctypes.c_int, ctypes.c_uint32, c_void_p]

# for debugging CreateWithBytes
CFURLGetBytes = CoreFoundation.CFURLGetBytes
CFURLGetBytes.restype = ctypes.c_int
CFURLGetBytes.argtypes = [c_void_p, ctypes.c_char_p, ctypes.c_int]

# get App associated with CFURL
LSCopyDefaultApplicationURLForURL = LaunchServices.LSCopyDefaultApplicationURLForURL
LSCopyDefaultApplicationURLForURL.restype = c_void_p
LSCopyDefaultApplicationURLForURL.argtypes = [c_void_p, c_void_p, c_void_p]

In [39]:

def app_for_url(url):
    """Returns file:// url for the app associated with a url"""
    cf_url = CFURLCreateWithBytes(
        None,
        url.encode('utf8'),
        len(url),
        kCFStringEncodingUTF8,
        None,
    )
    cf_app = LSCopyDefaultApplicationURLForURL(cf_url, None, None)
    if cf_app is None:
        raise ValueError("No app found for %s" % url)
    buf = (ctypes.c_char * 1024)()
    CFURLGetBytes(cf_app, buf, len(buf))
    return buf.value.decode('utf8')
    

In [40]:

app_for_url("http://google.com")

Out[40]:

'file:///Applications/Safari.app/'

Raises if there's no application found

In [41]:

import os
app_for_url("file://" + os.path.abspath("mac-detect-browser.ipynb"))

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-41-bd1a3a99e3f4> in <module>
      1 import os
----> 2 app_for_url("file://" + os.path.abspath("mac-detect-browser.ipynb"))

<ipython-input-39-d5c013765a13> in app_for_url(url)
     10     cf_app = LSCopyDefaultApplicationURLForURL(cf_url, None, None)
     11     if cf_app is None:
---> 12         raise ValueError("No app found for %s" % url)
     13     buf = (ctypes.c_char * 1024)()
     14     CFURLGetBytes(cf_app, buf, len(buf))

ValueError: No app found for file:///Users/benjaminrk/dev/mine/notebooks/empty/mac-detect-browser.ipynb

In [42]:

import os
app_for_url("file://" + os.path.abspath("untitled.txt"))

Out[42]:

'file:///Applications/Sublime+Text.app/'

webbrowser doesn't know how to handle absolute paths:

In [44]:

webbrowser.get("/Applications/Safari.app")

---------------------------------------------------------------------------
Error                                     Traceback (most recent call last)
<ipython-input-44-1f7ad1cf2a7d> in <module>
----> 1 webbrowser.get("/Applications/Safari.app")

~/conda/lib/python3.6/webbrowser.py in get(using)
     49             elif command[0] is not None:
     50                 return command[0]()
---> 51     raise Error("could not locate runnable browser")
     52 
     53 # Please note: the following definition hides a builtin function.

Error: could not locate runnable browser

So we pick out the base name of the .app and hope that works:

In [45]:

from urllib.parse import unquote

def app_name_for_url(url):
    """Return the name of an app associated with a url"""
    app = app_for_url(url)
    path = app.split('://', 1)[1]
    basename = path.rstrip('/')
    name, dotapp = os.path.splitext(os.path.basename(path.rstrip('/')))
    return unquote(name)

In [46]:

app_name_for_url('http://google.com')

Out[46]:

'Safari'

In [47]:

browser = webbrowser.get(app_name_for_url('http://jupyter.org'))
browser.open("file://" + os.path.abspath("test.html"))

Out[47]:

True