diff --git a/README.rst b/README.rst
index 03b8107..cbfd005 100644
--- a/README.rst
+++ b/README.rst
@@ -53,6 +53,8 @@ To install Wikipedia, simply run:
 
   $ pip install wikipedia
 
+After installation to define parameter 'WIKIPEDIA_PROJECT' with the path to the current project in system variables.
+
 Wikipedia is compatible with Python 2.6+ (2.7+ to run unittest discover) and Python 3.3+.
 
 Documentation
diff --git a/requirements.txt b/requirements.txt
index 130b5ae..fe649fe 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1,3 @@
+numpy
 beautifulsoup4
 requests>=2.0.0,<3.0.0
diff --git a/wikipedia/exceptions.py b/wikipedia/exceptions.py
index 0295b1c..014bb67 100644
--- a/wikipedia/exceptions.py
+++ b/wikipedia/exceptions.py
@@ -78,3 +78,10 @@ def __init__(self, query):
 
   def __unicode__(self):
     return u"Searching for \"{0}\" resulted in a timeout. Try again in a few seconds, and make sure you have rate limiting set to True.".format(self.query)
+
+
+class BadParameterException(WikipediaException):
+  """Exception raised when an incorrectly set parameter, such as language, query parameter and etc."""
+
+  def __unicode__(self):
+    return "The parameter is set incorrectly. {0}".format(self.error)
\ No newline at end of file
diff --git a/wikipedia/languages_tool.py b/wikipedia/languages_tool.py
new file mode 100644
index 0000000..88e5731
--- /dev/null
+++ b/wikipedia/languages_tool.py
@@ -0,0 +1,24 @@
+import csv
+import os
+
+from numpy.core.defchararray import lower
+
+from .exceptions import BadParameterException
+
+project_folder = "WIKIPEDIA_PROJECT"
+file_csv = "{0}{1}".format(os.environ.get(project_folder, None), "\\wikipedia\\list_languages.csv")
+
+
+def init_list_languages():
+  try:
+    with open(file_csv, newline='') as file:
+      reader = csv.reader(file)
+      return list(reader)
+  except FileNotFoundError:
+    raise BadParameterException("Make sure that the system variable '{0}' is set, "
+                                "the value of which must be the path to the current project".format(project_folder))
+
+
+def find_language(lst, param):
+  if lower(param) in lst:
+    return True
diff --git a/wikipedia/list_languages.csv b/wikipedia/list_languages.csv
new file mode 100644
index 0000000..d130c43
--- /dev/null
+++ b/wikipedia/list_languages.csv
@@ -0,0 +1,310 @@
+en
+ceb
+sv
+de
+fr
+nl
+ru
+it
+es
+pl
+war
+vi
+ja
+zh
+ar
+pt
+uk
+fa
+ca
+sr
+arz
+no
+id
+ko
+fi
+hu
+cs
+sh
+ro
+zh-min-nan
+eu
+tr
+ms
+eo
+hy
+he
+bg
+da
+ce
+azb
+sk
+kk
+min
+hr
+et
+lt
+be
+el
+sl
+gl
+simple
+az
+ur
+nn
+hi
+th
+ka
+uz
+la
+cy
+ta
+vo
+ast
+mk
+lv
+tg
+tt
+mg
+af
+bn
+oc
+zh-yue
+bs
+sq
+ky
+new
+tl
+be-tarask
+te
+ml
+br
+nds
+pms
+su
+sw
+ht
+lb
+vec
+jv
+mr
+sco
+pnb
+ga
+szl
+ba
+is
+my
+fy
+cv
+lmo
+an
+pa
+ne
+wuu
+yo
+bar
+io
+gu
+ku
+als
+ckb
+kn
+scn
+bpy
+ia
+qu
+mn
+diq
+bat-smg
+or
+si
+cdo
+nv
+ilo
+gd
+yi
+am
+nap
+bug
+xmf
+wa
+sd
+hsb
+mai
+map-bms
+fo
+mzn
+li
+eml
+os
+sah
+ps
+sa
+frr
+bcl
+ace
+zh-classical
+mrj
+mhr
+hif
+hak
+roa-tara
+pam
+nso
+km
+hyw
+se
+rue
+crh
+bh
+vls
+mi
+shn
+nds-nl
+nah
+as
+sc
+vep
+gan
+myv
+gor
+ab
+glk
+bo
+so
+co
+tk
+fiu-vro
+sn
+lrc
+kv
+csb
+ha
+gv
+udm
+ie
+ay
+pcd
+zea
+kab
+nrm
+ug
+lez
+stq
+kw
+haw
+frp
+lfn
+lij
+mwl
+gn
+gom
+rm
+mt
+lo
+lad
+koi
+fur
+olo
+sat
+dty
+dsb
+ang
+ext
+ln
+bjn
+cbk-zam
+dv
+ban
+ksh
+gag
+pfl
+pag
+pi
+tyv
+av
+zu
+awa
+bxr
+xal
+krc
+pap
+za
+pdc
+kaa
+rw
+arc
+szy
+to
+nov
+jam
+tpi
+kbp
+kbd
+ig
+na
+tet
+wo
+ki
+tcy
+inh
+jbo
+atj
+roa-rup
+bi
+lbe
+kg
+ty
+lg
+mdf
+srn
+xh
+gcr
+fj
+ltg
+chr
+sm
+got
+ak
+kl
+pih
+om
+cu
+tn
+tw
+st
+ts
+rmy
+bm
+chy
+nqo
+rn
+tum
+ny
+mnw
+ss
+ch
+pnt
+iu
+ady
+ks
+ve
+ee
+ik
+sg
+ff
+ti
+dz
+din
+cr
+ng
+cho
+kj
+mh
+ho
+ii
+aa
+mus
+hz
+kr
diff --git a/wikipedia/wikipedia.py b/wikipedia/wikipedia.py
index 7ad50e1..4465642 100644
--- a/wikipedia/wikipedia.py
+++ b/wikipedia/wikipedia.py
@@ -6,9 +6,10 @@
 from datetime import datetime, timedelta
 from decimal import Decimal
 
+from wikipedia.languages_tool import init_list_languages, find_language
 from .exceptions import (
-  PageError, DisambiguationError, RedirectError, HTTPTimeoutError,
-  WikipediaException, ODD_ERROR_MESSAGE)
+    PageError, DisambiguationError, RedirectError, HTTPTimeoutError,
+    WikipediaException, ODD_ERROR_MESSAGE, BadParameterException)
 from .util import cache, stdout_encode, debug
 import re
 
@@ -17,6 +18,7 @@
 RATE_LIMIT_MIN_WAIT = None
 RATE_LIMIT_LAST_CALL = None
 USER_AGENT = 'wikipedia (https://github.com/goldsmith/Wikipedia/)'
+LIST_LANGUAGES = init_list_languages()
 
 
 def set_lang(prefix):
@@ -28,12 +30,14 @@ def set_lang(prefix):
 
   .. note:: Make sure you search for page titles in the language that you have set.
   '''
-  global API_URL
-  API_URL = 'http://' + prefix.lower() + '.wikipedia.org/w/api.php'
-
-  for cached_func in (search, suggest, summary):
-    cached_func.clear_cache()
+  if find_language(LIST_LANGUAGES, prefix):
+    global API_URL
+    API_URL = 'http://' + prefix.lower() + '.wikipedia.org/w/api.php'
 
+    for cached_func in (search, suggest, summary):
+      cached_func.clear_cache()
+  else:
+    raise BadParameterException('The entered "language" parameter "{0}" is not supported by Wikipedia'.format(prefix))
 
 def set_user_agent(user_agent_string):
   '''
@@ -97,6 +101,8 @@ def search(query, results=10, suggestion=False):
     'limit': results,
     'srsearch': query
   }
+  if not query:
+    raise BadParameterException('The entered "query" parameter should not be empty')
   if suggestion:
     search_params['srinfo'] = 'suggestion'