from collections import defaultdict

def collect_dictionary(obj):
  inv_obj = defaultdict(list)
  for key, value in obj.items():
    inv_obj[value].append(key)
  return dict(inv_obj)
  
ages = {
  'Peter': 10,
  'Isabel': 10,
  'Anna': 9,
}
collect_dictionary(ages) # { 10: ['Peter', 'Isabel'], 9: ['Anna'] }

# @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, [''])

# Deleting all even numbers from a list
a = [1,2,3,4,5]
del a[1::2]
print(a)

def get_ldap_user(member_cn, user, passwrd):
    '''
    Get an LDAP user and return the SAMAccountName
    '''
    #---- Setting up the Connection
    #account used for binding - Avoid putting these in version control
    bindDN = str(user) + "@unt.ad.unt.edu"
    bindPass = passwrd

    #set some tuneables for the LDAP library.
    ldap.set_option(ldap.OPT_X_TLS_REQUIRE_CERT, ldap.OPT_X_TLS_ALLOW)
    #ldap.set_option(ldap.OPT_X_TLS_CACERTFILE, CACERTFILE)
    
    conn = ldap.initialize('ldaps://unt.ad.unt.edu')
    conn.protocol_version = 3
    conn.set_option(ldap.OPT_REFERRALS, 0)

    #authenticate the connection so that you can make additional queries
    try:
        result = conn.simple_bind_s(bindDN, bindPass) 
    except ldap.INVALID_CREDENTIALS:
        result = "Invalid credentials for %s" % user
        sys.exit()

    #build query in the form of (uid=user)
    ldap_query = '(|(displayName=' + member_cn + ')(cn='+ member_cn + ')(name=' + member_cn + '))'
    ldap_info = conn.search_s('DC=unt,DC=ad,DC=unt,DC=edu', ldap.SCOPE_SUBTREE, filterstr=ldap_query)
    sAMAccountName = str(ldap_info[0][1]['sAMAccountName']).replace("[b'", "").replace("']","")
    return sAMAccountName

my_list = ["blue", "red", "green"]

#1- Using sort or srted directly or with specifc keys
my_list.sort() #sorts alphabetically or in an ascending order for numeric data 
my_list = sorted(my_list, key=len) #sorts the list based on the length of the strings from shortest to longest. 
# You can use reverse=True to flip the order

#2- Using locale and functools 
import locale
from functools import cmp_to_key
my_list = sorted(my_list, key=cmp_to_key(locale.strcoll))

"""
Take screenshots at x interval - make a movie of doings on a computer.
"""

import time
from datetime import datetime

import ffmpeg
import pyautogui

while True:
    epoch_time = int(time.time())
    today = datetime.now().strftime("%Y_%m_%d")
    filename = str(epoch_time) + ".png"

    print("taking screenshot: {0}".format(filename))
    myScreenshot = pyautogui.screenshot()

    myScreenshot.save(today + "/" + filename)

    time.sleep(5)

#
# and then tie it together with: https://github.com/kkroening/ffmpeg-python/blob/master/examples/README.md#assemble-video-from-sequence-of-frames
#

"""
import ffmpeg
(
    ffmpeg
    .input('./2021_01_22/*.png', pattern_type='glob', framerate=25)
    .filter('deflicker', mode='pm', size=10)
    .filter('scale', size='hd1080', force_original_aspect_ratio='increase')
    .output('movie.mp4', crf=20, preset='slower', movflags='faststart', pix_fmt='yuv420p')
    .run()
)
"""