Словари

school = {'1а':20, '1б':21, '2а':15, '2б':33}
print (school)
number = input ('Введите номер класса: ')
print('В том классе учится', school[number], 'детей')
a = school['1а'] + 3
b = school['2а'] - 2
c = school['2б'] + 1
school['1а'] = a
school['2а'] = b
school['2б'] = c
print (school)

s=0
school={'1a':12,'1b':44,'2a':23,'2b':44}
school['1a']=school['1a']-3
school['3a']=65
del school['1b']
for i in school:
    s=s+school[i]
print("В школе всего {} учеников".format(s))

sl={1:'one', 2:'two', 3:'three', 4:'four', 5:'five'}
a = sl.items()
 
def transform(s):
    o = {}
    for key, value in a:
        o[value] = key
    print(o)
 
transform(a)
input('press enter')

def school():
    scDict={'1a':20,'1b':25,'1c':22,'2a':12,'2b':25,'2c':18}
    print('original dict:=',scDict)
 
    scDict['1b'] +=3
    print('the number of students in the class has changed',scDict)
 
    scDict.update({'3a':22})
    print('add new class \'3a\'',scDict)
 
    del scDict['2b']
    print('dell class \'2b\'',scDict)
 
    print('sum students in school:=',sum(scDict.values()))
 
def reverse():
    def revDict(incDict):
        nDict={}
        for key,value in incDict:
            nDict[value]=key
        return nDict
 
    mDict={1:'a',2:'b',3:'c',4:'d'}
 
    mdItems = revDict(mDict.items())
    print('original dict:={}\nreverse dict:={}'.format(mDict,mdItems))
 
school()
reverse()

school = {'1a':27, '1b':30, '1c':33, '7a':24, '7b':20}
print ('Original:' , school)
 
school['1a'] = 25
print ('A:', school)
 
school.setdefault('8c',35)
print ('B:', school)
 
school.pop('1a')
print ('C:', school)
 
print ('Total student in school:', sum(school.values()))

import random
from random import randint, randrange
def filling():
     c={}
     for i in range(0,5):
          a=randint(10,25)
          b=str(randrange(1,10,1))+chr(65+i)
          c[b]=a
     return c
#____________________________________
 
filling()
school=filling().copy()
total=[]
classes=[]
for i in school.values():
     total.append(i)
for i in school.keys():
     classes.append(i)
print(classes)     
print(school)
del1=randint(0,len(classes)-1)
print('Class {} was closed and Class {} was added'.format(classes[del1],'5P'))
deleted=school.pop(classes[del1])
school.update({'5P':randint(0,35)})
print(school, '\n Total students:',sum(total))

def transform(income):
     nl={}
     for key,value in income:
          nl[value]= key
     return nl
x={1:'uno',2:'due',3:'tre'}
z=x.copy().items()
transform(z)      
print(x)
print(transform(z))

school = {1:23, 2:16, 3:20, 4:14}
school[1] = 20 # класс уменьшился
school[0] = 5 # ввели нулевку
del school[4] # класс выпустился
print(sum(school.values()))

def rs(x):
 re_new = {}
 for w in x:
  re_new[w[1]]= w[0]
 print(re_new)
 
re = {1:"a", 2:"b"}
rs(re.items())

school = {'1a': 32, '1b': 29, '2b': 28, '6a': 18, '7b': 22}
for key, value in school.items():
    print(key, '=>', value)
 
school['1b'] += 2
school['8a'] = 10
school.pop('7b')
print(school, 'Общее кол-во учащихся: %s' % sum(school.values()), sep='\n')

def DictRevers(items):
    new_dict = {}
    for key, value in items:
        key, value = value, key
        new_dict.setdefault(key, value)
    return new_dict
 
a = {1: 'one', 2: 'two', 3: 'three'}
b = DictRevers(a.items())
print(b)

x = {1 : "Bir", 2 : "Eki", 3 : "Úsh"}
y = x.items()
def new_dict(a):
	new_dict = {}
	for key, value in a:
		new_dict.setdefault(value, key)
	return new_dict
print(new_dict(y))	
print(y)

from random import choice, randint
import string
 
def data_output(first_dict):
	for i in first_dict:
		print(f"Класс: {i}, Количество учеников: {first_dict[i]}")
 
def random_people(first_dict):
	key, value = choice(list(first_dict.items()))
	first_dict[key] = randint(10, 40)
	print(f"Случайный класс: -> {key} -> Изменение в учениках: {first_dict[key]}")
 
def add_classroom(first_dict):
	data = [str(randint(1, 9)) + choice(string.ascii_lowercase)]
	new_dict = dict.fromkeys(data, randint(10, 40))
	for k in new_dict:
		print(f"Новый классрум: {k} кол-во учащихся: {new_dict[k]}")
	first_dict.update(new_dict)
 
def total_stud_pop(first_dict):
	total = 0
	for x in first_dict.values():
		total += x
	print(total)
 
def del_classroom(first_dict):
	key = [v for v in choice(list(first_dict)).split()]
	for x in key:
		del first_dict[x]
	print(f"Удалили: {x}\nPROOF: {first_dict}")
 
school = {'1a': 10, '2b': 20, '3c': 30}
data_output(school)
random_people(school)
add_classroom(school)
total_stud_pop(school)
del_classroom(school)
total_stud_pop(school)

def flip_values(first_dict):
	new_dict = {}
	for key, value in first_dict:
		new_dict[value] = key
	print(new_dict)
 
dictionary = {1: 'one', 2: 'two', 3: 'three'}
dict_items = dictionary.items()
print(f"Before: {dictionary}")
print("After: ", end='')
flip_values(dict_items)

school = {'1a': 10,'1b': 12,'2b': 20,'6a': 15,'7b': 16}
 
def operations():
    print(school)
    try:
        opn = int(input('введите в поле что хотите получить: 1-изменить число учащ. , 2-удалить весь класс, 3- добавить класс > '))
    except ValueError:
        print('вводиь нужно число')
    if opn == 1:
        a = input('класс введите номер класса > ')
        b = input('число учащихся введите число > ')
        school[a] = b
        return school
        print(school)
    elif opn == 2:
        a = input('класс введите номер класса > ')
        school.pop(a)
        return school
    elif opn == 3:
        a = input('класс введите номер класса > ')
        b = input('число учащихся введите число > ')
        school.update({a:b})
        return school
operations()
print(school)

school = {'1a': 10, '1b': 12, '6a': 15, '7b': 16, '2b': 20} # остался с предыдущего задания
l3 = {}
def f(c):
    school1 = []
 
    for key, value in c:
        school1 = [value]
        c = dict.fromkeys(school1,key)
        l3.update(c)                    #получаем обратный словарь
 
    return school
 
 
c = school.items()
f(c)
print(school,'\n',"обратный словарь",'\n', l3)

school={'1a':15, '2a':10, '3a':20, '4b':25, '5b':15}
print(school)
number=input("Введите номер класса: ")
 
 
print("В этом классе учится -", school[number], 'детей')
school['2a']=15 #изменили колличество
print(school)
print("В этом классе учится -", school[number], 'детей')
 
school['6a']=10 #добавили класс
print(school)
 
school.pop('4b') #удалили класс
print(school)
s=0
for i in school:
  s+=school[i] # вычесляем колличество учеников путем перебора значения ключа
print(s)