# @return a list of strings, [s1, s2]
def letterCombinations(self, digits):
    if '' == digits: return []
    kvmaps = {
        '2': 'abc',
        '3': 'def',
        '4': 'ghi',
        '5': 'jkl',
        '6': 'mno',
        '7': 'pqrs',
        '8': 'tuv',
        '9': 'wxyz'
    }
    return reduce(lambda acc, digit: [x + y for x in acc for y in kvmaps[digit]], digits, [''])

x[cat_var].isnull().sum().sort_values(ascending=False)

import os
import sys
import argparse
import json
import csv
import getpass
import string
import random
import re

from datetime import datetime
import ldap
import requests
from requests.packages.urllib3.exceptions import InsecureRequestWarning
requests.packages.urllib3.disable_warnings(InsecureRequestWarning)
from requests.auth import HTTPBasicAuth
import validators



def create_guac_connection(BASE_URL, auth_token, ldap_group, computer, guac_group_id):
    '''
    creates a guac connection
    '''
    json_header = {'Accept': 'application/json'}
    query_parm_payload = { 'token': auth_token }

    payload_data = {
   "parentIdentifier":guac_group_id,
   "name":computer,
   "protocol":"vnc",
   "parameters":{
      "port":"5900",
      "read-only":"",
      "swap-red-blue":"",
      "cursor":"",
      "color-depth":"",
      "clipboard-encoding":"",
      "disable-copy":"",
      "disable-paste":"",
      "dest-port":"",
      "recording-exclude-output":"",
      "recording-exclude-mouse":"",
      "recording-include-keys":"",
      "create-recording-path":"",
      "enable-sftp":"true",
      "sftp-port":"",
      "sftp-server-alive-interval":"",
      "enable-audio":"",
      "audio-servername":"",
      "sftp-directory":"",
      "sftp-root-directory":"",
      "sftp-passphrase":"",
      "sftp-private-key":"",
      "sftp-username":"",
      "sftp-password":"",
      "sftp-host-key":"",
      "sftp-hostname":"",
      "recording-name":"",
      "recording-path":"",
      "dest-host":"",
      "password":"asdasd",
      "username":"asdasd",
      "hostname":"nt72310.cvad.unt.edu"
   },
   "attributes":{
      "max-connections":"",
      "max-connections-per-user":"1",
      "weight":"",
      "failover-only":"",
      "guacd-port":"",
      "guacd-encryption":"",
      "guacd-hostname":""
   }
}
    CREATE_CONNECTION_URL = BASE_URL + "/api/session/data/mysql/connections"

    create_connection_request = requests.post(CREATE_CONNECTION_URL, headers=json_header, params=query_parm_payload, data=payload_data, verify=False)
    create_connection_result = create_connection_request.status_code


    if create_connection_result == "200":
        print("Successfully created computer: " + computer)
    else: 
        print(create_connection_request.json())

    return create_connection_result

#Sets
U = {0,1,2,3,4,5,6,7,8,9}
P = {1,2,3,4}
Q = {4,5,6}
R = {3,4,6,8,9}

def set2bits(xs,us) :
    bs=[]
    for x in us :
        if x in xs :
            bs.append(1)
        else:
            bs.append(0)
    assert len(us) == len(bs)
    return bs

def union(set1,set2) :
    finalSet = set()
    bitList1 = set2bits(set1, U)
    bitList2 = set2bits(set2, U)

    for i in range(len(U)) :
        if(bitList1[i] or bitList2[i]) :
            finalSet.add(i)

    return finalSet

def intersection(set1,set2) :
    finalSet = set()
    bitList1 = set2bits(set1, U)
    bitList2 = set2bits(set2, U)

    for i in range(len(U)) :
        if(bitList1[i] and bitList2[i]) :
            finalSet.add(i)

    return finalSet

def compliment(set1) :
    finalSet = set()
    bitList = set2bits(set1, U)

    for i in range(len(U)) :
        if(not bitList[i]) :
            finalSet.add(i)

    return finalSet

def implication(a,b):
    return union(compliment(a), b)

###########################################################################################
######################         Problems 1-6         #######################################
###########################################################################################

#p \/ (q /\ r) = (p \/ q) /\ (p \/ r)
def prob1():
    return union(P, intersection(Q,R)) == intersection(union(P,Q), union(P,R))

#p /\ (q \/ r) = (p /\ q) \/ (p /\ r)
def prob2():
    return intersection(P, union(Q,R)) == union(intersection(P,Q), intersection(P,R))

#~(p /\ q) = ~p \/ ~q
def prob3():
    return compliment(intersection(P,R)) == union(compliment(P), compliment(R))

#~(p \/ q) = ~p /\ ~q
def prob4():
    return compliment(union(P,Q)) == intersection(compliment(P), compliment(Q))

#(p=>q) = (~q => ~p)
def prob5():
    return implication(P,Q) == implication(compliment(Q), compliment(P))

#(p => q) /\ (q => r)  =>  (p => r)
def prob6():
    return implication(intersection(implication(P,Q), implication(Q,R)), implication(P,R))


print("Problem 1: ", prob1())
print("Problem 2: ", prob2())
print("Problem 3: ", prob3())
print("Problem 4: ", prob4())
print("Problem 5: ", prob5())
print("Problem 6: ", prob6())

'''
Problem 1:  True
Problem 2:  True
Problem 3:  True
Problem 4:  True
Problem 5:  True
Problem 6:  {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
'''

# question3.py
from itertools import product
V='∀'
E='∃'

def tt(f,n) :
  xss=product((0,1),repeat=n)
  print('function:',f.__name__)
  for xs in xss : print(*xs,':',int(f(*xs)))
  print('')

# this is the logic for part A (p\/q\/r) /\ (p\/q\/~r) /\ (p\/~q\/r) /\ (p\/~q\/~r) /\ (~p\/q\/r) /\ (~p\/q\/~r) /\ (~p\/~q\/r) /\ (~p\/~q\/~r)

def parta(p,q,r) :
  
  a=(p or q or r) and (p or q or not r) and (p or not q or r)and (p or not q or  not r)
  b=(not p or q or r ) and (not p or q or not r) and (not p or not q or r) and (not p or not q or not r)
  c= a and b
  return c

def partb(p,q,r) :
  a=(p or q and r) and (p or not q or not r) and (p or not q or not  r)and (p or q or  not r)
  b=(not p or q or r ) and (not p or q or not r) and (not p or not q or r) and (not p or not q or not r)
  c= a and b
  return c

print("part A:")
tt(parta,3)

print("part B:")
tt(partb,3)

# function which return reverse of a string
def isPalindrome(s):
    return s == s[::-1]
 
# Driver code
s = "malayalam"
ans = isPalindrome(s)
 
if ans:
    print("Yes")
else:
    print("No")