How do I check the version of the Selenium API installed?

Here's how i checked for the version of selenium in Python.

>>> import selenium    
>>> help (selenium)
Help on package selenium:

NAME
    selenium

FILE
    c:\python27\lib\site-packages\selenium\__init__.py

DESCRIPTION
    # Licensed to the Software Freedom Conservancy (SFC) under one
    # or more contributor license agreements.  See the NOTICE file
    # distributed with this work for additional information
    # regarding copyright ownership.  The SFC licenses this file
    # to you under the Apache License, Version 2.0 (the
    # "License"); you may not use this file except in compliance
    # with the License.  You may obtain a copy of the License at
    #
    #   http://www.apache.org/licenses/LICENSE-2.0
    #
    # Unless required by applicable law or agreed to in writing,
    # software distributed under the License is distributed on an
    # "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    # KIND, either express or implied.  See the License for the
    # specific language governing permissions and limitations
    # under the License.

PACKAGE CONTENTS
    common (package)
    selenium
    webdriver (package)

DATA
    __version__ = '2.48.0'

VERSION
    2.48.0

You can also run locate selenium in the terminal, and you can see the version number in the file names.

Python 2.7.6 (default, Mar 22 2014, 22:59:56)
[GCC 4.8.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import selenium
>>> print selenium.__version__
3.3.0

You would have referenced the jar's in your IDE (Eclipse or whatever you are using maybe). Check build path libraries. See the ScreenShot below:-

Another way of determining the Selenium version is through the command line:

dpkg-query --list '*selenium*'

Output:

Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name                                                Version                        Architecture                   Description
+++-===================================================-==============================-==============================-===========================================================================================================
ii  python-selenium                                     2.48.0+dfsg1-2                 all                            Python bindings for Selenium