# @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, [''])

from statistics import median, mean, mode

def print_stats(array):
  print(array)
  print("median =", median(array))
  print("mean   =", mean(array))
  print("mode   =", mode(array))
  print()

print_stats([1, 2, 3, 3, 4])
print_stats([1, 2, 3, 3])

import mysql.connector

mydb = mysql.connector.connect(
  host="localhost",
  user="yourusername",
  password="yourpassword"
)

mycursor = mydb.cursor()

mycursor.execute("CREATE DATABASE mydatabase")

def clamp_number(num, a, b):
  return max(min(num, max(a, b)), min(a, b))
  
clamp_number(2, 3, 5) # 3
clamp_number(1, -1, -5) # -1

""" Currency Converter
----------------------------------------
"""
import urllib.request
import json
def currency_converter(currency_from, currency_to, currency_input):
    yql_base_url = "https://query.yahooapis.com/v1/public/yql"
    yql_query = 'select%20*%20from%20yahoo.finance.xchange%20where%20pair' \
                '%20in%20("'+currency_from+currency_to+'")'
    yql_query_url = yql_base_url + "?q=" + yql_query + "&format=json&env=store%3A%2F%2Fdatatables.org%2Falltableswithkeys"
    try:
        yql_response = urllib.request.urlopen(yql_query_url)
        try:
            json_string = str(yql_response.read())
            json_string = json_string[2:
            json_string = json_string[:-1]
            print(json_string)
            yql_json = json.loads(json_string)
            last_rate = yql_json['query']['results']['rate']['Rate']
            currency_output = currency_input * float(last_rate)
            return currency_output
        except (ValueError, KeyError, TypeError):
            print(yql_query_url)
            return "JSON format error"
    except IOError as e:
        print(str(e))
currency_input = 1
#currency codes : http://en.wikipedia.org/wiki/ISO_4217
currency_from = "USD"
currency_to = "TRY"
rate = currency_converter(currency_from, currency_to, currency_input)
print(rate)