List of all imports in python 3

Question

How to find out list of all available imports in python 3 via program? I tried this at first, but couldn't understand what it returned

import sys
    sys.modules

I think this isn't the way, although this struck my mind first. I searched the web and found this http://effbot.org/librarybook/core-modules-index.htm

Can someone tell me whether this is correct or not?

Answer 1

From http://docs.python.org/library/sys.html (a good place to look for documentation on python stdlib)

sys.builtin_module_names

is a tuple (a bit like a immutable anonymous structs) of strings giving the names of all modules that are compiled into this Python interpreter.

sys.modules

This is a dictionary that maps module names to modules (module objects) which have already been loaded. This can be manipulated to force reloading of modules and other tricks. Note that removing a module from this dictionary is not the same as calling reload() on the corresponding module object.

So modules is a dictionary (a mapping of module names to the actual module objects). To get just the names type sys.modules.keys() although it probably isn't that usefull.

Answer 2

Worked as with the Python 2 and the Python 3 (tested with the next version of the 2.7, 3.4, 3.5)

import shutil
import pkgutil

def show_acceptable_modules():
    line = '-' * 100
    print('{}\n{:^30}|{:^20}\n{}'.format(line, 'Module', 'Location', line))
    for entry in pkgutil.iter_modules():
        print('{:30}| {}'.format(entry[1], entry[0].path))

Sample output for the Python 2.7

>>> show_acceptable_modules()
----------------------------------------------------------------------------------------------------
            Module            |      Location      
----------------------------------------------------------------------------------------------------
ANSI                          | /usr/lib/python2.7/dist-packages
BaseHTTPServer                | /usr/lib/python2.7
Bastion                       | /usr/lib/python2.7
CDROM                         | /usr/lib/python2.7/plat-x86_64-linux-gnu
CGIHTTPServer                 | /usr/lib/python2.7
Canvas                        | /usr/lib/python2.7/lib-tk
ConfigParser                  | /usr/lib/python2.7
Cookie                        | /usr/lib/python2.7
DLFCN                         | /usr/lib/python2.7/plat-x86_64-linux-gnu
Dialog                        | /usr/lib/python2.7/lib-tk
DocXMLRPCServer               | /usr/lib/python2.7
FSM                           | /usr/lib/python2.7/dist-packages
FileDialog                    | /usr/lib/python2.7/lib-tk
FixTk                         | /usr/lib/python2.7/lib-tk
HTMLParser                    | /usr/lib/python2.7
IN                            | /usr/lib/python2.7/plat-x86_64-linux-gnu
Image                         | /usr/lib/python2.7/dist-packages/PILcompat
ImageChops                    | /usr/lib/python2.7/dist-packages/PILcompat
ImageColor                    | /usr/lib/python2.7/dist-packages/PILcompat
ImageCrackCode                | /usr/lib/python2.7/dist-packages/PILcompat
ImageDraw                     | /usr/lib/python2.7/dist-packages/PILcompat
ImageEnhance                  | /usr/lib/python2.7/dist-packages/PILcompat
ImageFile                     | /usr/lib/python2.7/dist-packages/PILcompat
ImageFileIO                   | /usr/lib/python2.7/dist-packages/PILcompat
ImageFilter                   | /usr/lib/python2.7/dist-packages/PILcompat
ImageFont                     | /usr/lib/python2.7/dist-packages/PILcompat
ImageGL                       | /usr/lib/python2.7/dist-packages/PILcompat
ImageGrab                     | /usr/lib/python2.7/dist-packages/PILcompat
ImageMath                     | /usr/lib/python2.7/dist-packages/PILcompat
ImageOps                      | /usr/lib/python2.7/dist-packages/PILcompat
ImagePalette                  | /usr/lib/python2.7/dist-packages/PILcompat
ImagePath                     | /usr/lib/python2.7/dist-packages/PILcompat
ImageQt                       | /usr/lib/python2.7/dist-packages/PILcompat
ImageSequence                 | /usr/lib/python2.7/dist-packages/PILcompat
ImageStat                     | /usr/lib/python2.7/dist-packages/PILcompat
ImageTk                       | /usr/lib/python2.7/dist-packages/PILcompat
ImageWin                      | /usr/lib/python2.7/dist-packages/PILcompat
MimeWriter                    | /usr/lib/python2.7
ORBit                         | /usr/lib/pymodules/python2.7
PIL                           | /usr/lib/python2.7/dist-packages
PSDraw                        | /usr/lib/python2.7/dist-packages/PILcompat
PngImagePlugin                | /usr/lib/python2.7/dist-packages/PILcompat
Queue                         | /usr/lib/python2.7
SOAPpy                        | /usr/lib/python2.7/dist-packages
ScrolledText                  | /usr/lib/python2.7/lib-tk
SimpleDialog                  | /usr/lib/python2.7/lib-tk
SimpleHTTPServer              | /usr/lib/python2.7
SimpleXMLRPCServer            | /usr/lib/python2.7
SocketServer                  | /usr/lib/python2.7
StringIO                      | /usr/lib/python2.7
TYPES                         | /usr/lib/python2.7/plat-x86_64-linux-gnu
Tix                           | /usr/lib/python2.7/lib-tk
Tkconstants                   | /usr/lib/python2.7/lib-tk
Tkdnd                         | /usr/lib/python2.7/lib-tk
Tkinter                       | /usr/lib/python2.7/lib-tk
UserDict                      | /usr/lib/python2.7
UserList                      | /usr/lib/python2.7
UserString                    | /usr/lib/python2.7
_LWPCookieJar                 | /usr/lib/python2.7
_MozillaCookieJar             | /usr/lib/python2.7
__future__                    | /usr/lib/python2.7
_abcoll                       | /usr/lib/python2.7
_bsddb                        | /usr/lib/python2.7/lib-dynload
_codecs_cn                    | /usr/lib/python2.7/lib-dynload
_codecs_hk                    | /usr/lib/python2.7/lib-dynload
_codecs_iso2022               | /usr/lib/python2.7/lib-dynload
_codecs_jp                    | /usr/lib/python2.7/lib-dynload
_codecs_kr                    | /usr/lib/python2.7/lib-dynload
_codecs_tw                    | /usr/lib/python2.7/lib-dynload
_csv                          | /usr/lib/python2.7/lib-dynload
_ctypes                       | /usr/lib/python2.7/lib-dynload
_ctypes_test                  | /usr/lib/python2.7/lib-dynload
_curses                       | /usr/lib/python2.7/lib-dynload
_curses_panel                 | /usr/lib/python2.7/lib-dynload
_dbus_bindings                | /usr/lib/python2.7/dist-packages
_dbus_glib_bindings           | /usr/lib/python2.7/dist-packages
_elementtree                  | /usr/lib/python2.7/lib-dynload
_hashlib                      | /usr/lib/python2.7/lib-dynload
_hotshot                      | /usr/lib/python2.7/lib-dynload
_json                         | /usr/lib/python2.7/lib-dynload
_lsprof                       | /usr/lib/python2.7/lib-dynload
_multibytecodec               | /usr/lib/python2.7/lib-dynload
_multiprocessing              | /usr/lib/python2.7/lib-dynload
_osx_support                  | /usr/lib/python2.7
_pyio                         | /usr/lib/python2.7
_smbc                         | /usr/lib/python2.7/dist-packages
_sqlite3                      | /usr/lib/python2.7/lib-dynload
_ssl                          | /usr/lib/python2.7/lib-dynload
_strptime                     | /usr/lib/python2.7
_sysconfigdata                | /usr/lib/python2.7
_sysconfigdata_nd             | /usr/lib/python2.7/plat-x86_64-linux-gnu
_testcapi                     | /usr/lib/python2.7/lib-dynload
_threading_local              | /usr/lib/python2.7
_weakrefset                   | /usr/lib/python2.7
abc                           | /usr/lib/python2.7
aifc                          | /usr/lib/python2.7
antigravity                   | /usr/lib/python2.7
anydbm                        | /usr/lib/python2.7
apt                           | /usr/lib/python2.7/dist-packages
apt_inst                      | /usr/lib/python2.7/dist-packages
apt_pkg                       | /usr/lib/python2.7/dist-packages
aptsources                    | /usr/lib/python2.7/dist-packages
argparse                      | /usr/lib/python2.7
ast                           | /usr/lib/python2.7
asynchat                      | /usr/lib/python2.7
asyncore                      | /usr/lib/python2.7
atexit                        | /usr/lib/python2.7
atk                           | /usr/lib/python2.7/dist-packages/gtk-2.0
audiodev                      | /usr/lib/python2.7
audioop                       | /usr/lib/python2.7/lib-dynload
base64                        | /usr/lib/python2.7
bdb                           | /usr/lib/python2.7
binhex                        | /usr/lib/python2.7
bisect                        | /usr/lib/python2.7
bonobo                        | /usr/lib/python2.7/dist-packages/gtk-2.0
bsddb                         | /usr/lib/python2.7
bz2                           | /usr/lib/python2.7/lib-dynload
cProfile                      | /usr/lib/python2.7
cairo                         | /usr/lib/pymodules/python2.7
calendar                      | /usr/lib/python2.7
caribou                       | /usr/lib/python2.7/dist-packages
cgi                           | /usr/lib/python2.7
cgitb                         | /usr/lib/python2.7
chardet                       | /usr/lib/python2.7/dist-packages
chunk                         | /usr/lib/python2.7
cmd                           | /usr/lib/python2.7
code                          | /usr/lib/python2.7
codecs                        | /usr/lib/python2.7
codeop                        | /usr/lib/python2.7
collections                   | /usr/lib/python2.7
colorlog                      | /usr/lib/python2.7/dist-packages
colorsys                      | /usr/lib/python2.7
commands                      | /usr/lib/python2.7
compileall                    | /usr/lib/python2.7
compiler                      | /usr/lib/python2.7
contextlib                    | /usr/lib/python2.7
cookielib                     | /usr/lib/python2.7
copy                          | /usr/lib/python2.7
copy_reg                      | /usr/lib/python2.7
crypt                         | /usr/lib/python2.7/lib-dynload
csv                           | /usr/lib/python2.7
ctypes                        | /usr/lib/python2.7
cups                          | /usr/lib/python2.7/dist-packages
cupsext                       | /usr/lib/python2.7/dist-packages
cupshelpers                   | /usr/lib/python2.7/dist-packages
curl                          | /usr/lib/python2.7/dist-packages
curses                        | /usr/lib/python2.7
dbhash                        | /usr/lib/python2.7
dbm                           | /usr/lib/python2.7/lib-dynload
dbus                          | /usr/lib/python2.7/dist-packages
deb822                        | /usr/lib/python2.7/dist-packages
debconf                       | /usr/lib/python2.7/dist-packages
debian                        | /usr/lib/python2.7/dist-packages
debian_bundle                 | /usr/lib/python2.7/dist-packages
debianbts                     | /usr/lib/pymodules/python2.7
decimal                       | /usr/lib/python2.7
defusedxml                    | /usr/lib/python2.7/dist-packages
difflib                       | /usr/lib/python2.7
dircache                      | /usr/lib/python2.7
dis                           | /usr/lib/python2.7
distutils                     | /usr/lib/python2.7
doctest                       | /usr/lib/python2.7
docutils                      | /usr/lib/python2.7/dist-packages
drv_libxml2                   | /usr/lib/python2.7/dist-packages
dsextras                      | /usr/lib/python2.7/dist-packages/gtk-2.0
dumbdbm                       | /usr/lib/python2.7
dummy_thread                  | /usr/lib/python2.7
dummy_threading               | /usr/lib/python2.7
email                         | /usr/lib/python2.7
encodings                     | /usr/lib/python2.7
ensurepip                     | /usr/lib/python2.7
fdpexpect                     | /usr/lib/python2.7/dist-packages
filecmp                       | /usr/lib/python2.7
fileinput                     | /usr/lib/python2.7
fnmatch                       | /usr/lib/python2.7
formatter                     | /usr/lib/python2.7
fpectl                        | /usr/lib/python2.7/lib-dynload
fpformat                      | /usr/lib/python2.7
fractions                     | /usr/lib/python2.7
ftplib                        | /usr/lib/python2.7
functools                     | /usr/lib/python2.7
future_builtins               | /usr/lib/python2.7/lib-dynload
gconf                         | /usr/lib/python2.7/dist-packages/gtk-2.0
genericpath                   | /usr/lib/python2.7
getopt                        | /usr/lib/python2.7
getpass                       | /usr/lib/python2.7
gettext                       | /usr/lib/python2.7
gi                            | /usr/lib/python2.7/dist-packages
gio                           | /usr/lib/python2.7/dist-packages/gtk-2.0
glib                          | /usr/lib/python2.7/dist-packages
glob                          | /usr/lib/python2.7
gnome                         | /usr/lib/python2.7/dist-packages/gtk-2.0
gnomecanvas                   | /usr/lib/python2.7/dist-packages/gtk-2.0
gnomevfs                      | /usr/lib/python2.7/dist-packages/gtk-2.0
gobject                       | /usr/lib/python2.7/dist-packages
gtk                           | /usr/lib/python2.7/dist-packages/gtk-2.0
gtkunixprint                  | /usr/lib/python2.7/dist-packages/gtk-2.0
gtweak                        | /usr/lib/python2.7/dist-packages
guake                         | /usr/lib/python2.7/dist-packages
gzip                          | /usr/lib/python2.7
hamster                       | /usr/lib/python2.7/dist-packages
hashlib                       | /usr/lib/python2.7
heapq                         | /usr/lib/python2.7
hgext                         | /usr/lib/python2.7/dist-packages
hmac                          | /usr/lib/python2.7
hotshot                       | /usr/lib/python2.7
hpmudext                      | /usr/lib/python2.7/dist-packages
htmlentitydefs                | /usr/lib/python2.7
htmllib                       | /usr/lib/python2.7
httplib                       | /usr/lib/python2.7
ihooks                        | /usr/lib/python2.7
imaplib                       | /usr/lib/python2.7
imghdr                        | /usr/lib/python2.7
importlib                     | /usr/lib/python2.7
imputil                       | /usr/lib/python2.7
inspect                       | /usr/lib/python2.7
io                            | /usr/lib/python2.7
json                          | /usr/lib/python2.7
keyword                       | /usr/lib/python2.7
lib2to3                       | /usr/lib/python2.7
libxml2                       | /usr/lib/python2.7/dist-packages
libxml2mod                    | /usr/lib/python2.7/dist-packages
linecache                     | /usr/lib/python2.7
linuxaudiodev                 | /usr/lib/python2.7/lib-dynload
locale                        | /usr/lib/python2.7
logging                       | /usr/lib/python2.7
lsb_release                   | /usr/lib/python2.7/dist-packages
lxml                          | /usr/lib/python2.7/dist-packages
macpath                       | /usr/lib/python2.7
macurl2path                   | /usr/lib/python2.7
mailbox                       | /usr/lib/python2.7
mailcap                       | /usr/lib/python2.7
markupbase                    | /usr/lib/python2.7
md5                           | /usr/lib/python2.7
mercurial                     | /usr/lib/python2.7/dist-packages
mhlib                         | /usr/lib/python2.7
mimetools                     | /usr/lib/python2.7
mimetypes                     | /usr/lib/python2.7
mimify                        | /usr/lib/python2.7
mmap                          | /usr/lib/python2.7/lib-dynload
modulefinder                  | /usr/lib/python2.7
multifile                     | /usr/lib/python2.7
multiprocessing               | /usr/lib/python2.7
mutex                         | /usr/lib/python2.7
ndiff                         | /usr/lib/python2.7/dist-packages
netrc                         | /usr/lib/python2.7
new                           | /usr/lib/python2.7
nis                           | /usr/lib/python2.7/lib-dynload
nntplib                       | /usr/lib/python2.7
ntpath                        | /usr/lib/python2.7
nturl2path                    | /usr/lib/python2.7
numbers                       | /usr/lib/python2.7
numpy                         | /usr/lib/python2.7/dist-packages
opcode                        | /usr/lib/python2.7
optparse                      | /usr/lib/python2.7
os                            | /usr/lib/python2.7
os2emxpath                    | /usr/lib/python2.7
ossaudiodev                   | /usr/lib/python2.7/lib-dynload
pango                         | /usr/lib/python2.7/dist-packages/gtk-2.0
pangocairo                    | /usr/lib/python2.7/dist-packages/gtk-2.0
parser                        | /usr/lib/python2.7/lib-dynload
pcardext                      | /usr/lib/python2.7/dist-packages
pdb                           | /usr/lib/python2.7
pexpect                       | /usr/lib/python2.7/dist-packages
pickle                        | /usr/lib/python2.7
pickletools                   | /usr/lib/python2.7
pipes                         | /usr/lib/python2.7
pkg_resources                 | /usr/lib/python2.7/dist-packages
pkgutil                       | /usr/lib/python2.7
platform                      | /usr/lib/python2.7
plistlib                      | /usr/lib/python2.7
popen2                        | /usr/lib/python2.7
poplib                        | /usr/lib/python2.7
posixfile                     | /usr/lib/python2.7
posixpath                     | /usr/lib/python2.7
pprint                        | /usr/lib/python2.7
profile                       | /usr/lib/python2.7
pstats                        | /usr/lib/python2.7
pty                           | /usr/lib/python2.7
pxssh                         | /usr/lib/python2.7/dist-packages
py_compile                    | /usr/lib/python2.7
pyatspi                       | /usr/lib/python2.7/dist-packages
pyclbr                        | /usr/lib/python2.7
pycurl                        | /usr/lib/python2.7/dist-packages
pydoc                         | /usr/lib/python2.7
pydoc_data                    | /usr/lib/python2.7
pyexpat                       | /usr/lib/python2.7/lib-dynload
pygments                      | /usr/lib/python2.7/dist-packages
pygtk                         | /usr/lib/python2.7/dist-packages
pygtkcompat                   | /usr/lib/python2.7/dist-packages
pynotify                      | /usr/lib/python2.7/dist-packages/gtk-2.0
quopri                        | /usr/lib/python2.7
random                        | /usr/lib/python2.7
re                            | /usr/lib/python2.7
readline                      | /usr/lib/python2.7/lib-dynload
reportbug                     | /usr/lib/python2.7/dist-packages
reportlab                     | /usr/lib/python2.7/dist-packages
repr                          | /usr/lib/python2.7
resource                      | /usr/lib/python2.7/lib-dynload
rexec                         | /usr/lib/python2.7
rfc822                        | /usr/lib/python2.7
rlcompleter                   | /usr/lib/python2.7
robotparser                   | /usr/lib/python2.7
roman                         | /usr/lib/python2.7/dist-packages
runpy                         | /usr/lib/python2.7
scanext                       | /usr/lib/python2.7/dist-packages
sched                         | /usr/lib/python2.7
screen                        | /usr/lib/python2.7/dist-packages
sets                          | /usr/lib/python2.7
sgmllib                       | /usr/lib/python2.7
sha                           | /usr/lib/python2.7
shelve                        | /usr/lib/python2.7
shlex                         | /usr/lib/python2.7
shutil                        | /usr/lib/python2.7
site                          | /usr/lib/python2.7
sitecustomize                 | /usr/lib/python2.7
six                           | /usr/lib/python2.7/dist-packages
smbc                          | /usr/lib/python2.7/dist-packages
smtpd                         | /usr/lib/python2.7
smtplib                       | /usr/lib/python2.7
sndhdr                        | /usr/lib/python2.7
socket                        | /usr/lib/python2.7
sqlite3                       | /usr/lib/python2.7
sre                           | /usr/lib/python2.7
sre_compile                   | /usr/lib/python2.7
sre_constants                 | /usr/lib/python2.7
sre_parse                     | /usr/lib/python2.7
ssl                           | /usr/lib/python2.7
stat                          | /usr/lib/python2.7
statvfs                       | /usr/lib/python2.7
string                        | /usr/lib/python2.7
stringold                     | /usr/lib/python2.7
stringprep                    | /usr/lib/python2.7
struct                        | /usr/lib/python2.7
subprocess                    | /usr/lib/python2.7
sunau                         | /usr/lib/python2.7
sunaudio                      | /usr/lib/python2.7
symbol                        | /usr/lib/python2.7
symtable                      | /usr/lib/python2.7
sysconfig                     | /usr/lib/python2.7
tabnanny                      | /usr/lib/python2.7
talloc                        | /usr/lib/python2.7/dist-packages
tarfile                       | /usr/lib/python2.7
telnetlib                     | /usr/lib/python2.7
tempfile                      | /usr/lib/python2.7
termios                       | /usr/lib/python2.7/lib-dynload
test                          | /usr/lib/python2.7
textwrap                      | /usr/lib/python2.7
this                          | /usr/lib/python2.7
threading                     | /usr/lib/python2.7
timeit                        | /usr/lib/python2.7
tkColorChooser                | /usr/lib/python2.7/lib-tk
tkCommonDialog                | /usr/lib/python2.7/lib-tk
tkFileDialog                  | /usr/lib/python2.7/lib-tk
tkFont                        | /usr/lib/python2.7/lib-tk
tkMessageBox                  | /usr/lib/python2.7/lib-tk
tkSimpleDialog                | /usr/lib/python2.7/lib-tk
toaiff                        | /usr/lib/python2.7
token                         | /usr/lib/python2.7
tokenize                      | /usr/lib/python2.7
trace                         | /usr/lib/python2.7
traceback                     | /usr/lib/python2.7
ttk                           | /usr/lib/python2.7/lib-tk
tty                           | /usr/lib/python2.7
turtle                        | /usr/lib/python2.7/lib-tk
types                         | /usr/lib/python2.7
unittest                      | /usr/lib/python2.7
urllib                        | /usr/lib/python2.7
urllib2                       | /usr/lib/python2.7
urlparse                      | /usr/lib/python2.7
user                          | /usr/lib/python2.7
uu                            | /usr/lib/python2.7
uuid                          | /usr/lib/python2.7
vboxapi                       | /usr/lib/python2.7/dist-packages
vte                           | /usr/lib/python2.7/dist-packages/gtk-2.0
warnings                      | /usr/lib/python2.7
wave                          | /usr/lib/python2.7
weakref                       | /usr/lib/python2.7
webbrowser                    | /usr/lib/python2.7
whichdb                       | /usr/lib/python2.7
wnck                          | /usr/lib/python2.7/dist-packages/gtk-2.0
wsgiref                       | /usr/lib/python2.7
wstools                       | /usr/lib/python2.7/dist-packages
xdg                           | /usr/lib/python2.7/dist-packages
xdrlib                        | /usr/lib/python2.7
xml                           | /usr/lib/python2.7
xmllib                        | /usr/lib/python2.7
xmlrpclib                     | /usr/lib/python2.7
zeitgeist                     | /usr/lib/python2.7/dist-packages
zipfile                       | /usr/lib/python2.7

Testing environment

$ lsb_release -a
No LSB modules are available.
Distributor ID: Debian
Description:    Debian GNU/Linux 8.6 (jessie)
Release:    8.6
Codename:   jessie
$ uname -a
Linux localhost 3.16.0-4-amd64 #1 SMP Debian 3.16.36-1+deb8u2 (2016-10-19) x86_64 GNU/Linux
$ python2 --version
Python 2.7.9
$ python3.4 --version
Python 3.4.2
$ python3.5 --version
Python 3.5.2