TypeError：“ int”对象在Python中不可调用

Question

Bit of a python noob and I'm required to add a regular expression in my code but can not get it to work :/ i have searched the error message on google and tried to figure out whats wrong but no luck so i figured next best thing to do would be to ask directly. Here is the code so far:

# allows us to access a random 'key' in the dictionary
import random
import re

# Contains the question and it's correct answer
my_dict =   {
            "A form of Protectionism that imposes a tax on imports" : "tariff",
            "....is quantity of a good or service that consumers are willing and able to     buy at a given price in a given time period" : "Demand", 
            "....is the quantity of a good or service that a producer is willing and able   to supply onto the market at a given price in a given time period" : "Supply",
            "By using ..... businesses can bring down their average costs by producing on a larger scale" : "Economies of scale",
            "The cost of the next best alternative" : "Opportunity Cost",
            ".... is the transfer of assets from the public (government) sector to the private sector." : "Privatisation"
        }


# welcome message
print("Economics Revision App")
print("=======================")



# the quiz will end when this variable becomes 'False'
playing = True


# While the game is running
while playing == True:

    # set the score to 0
    score = 0

    # gets the number of questions the player wants to answer
    num = int(input("\nHow many questions would you like: "))
    num = re.match("r\d[0-9]{2}$", num())
    if match:
        print ('foo')

    # loop the correct number of times
    for i in range(num):

        # the question is one of the dictionary keys, picked at random
        question = (random.choice( list(my_dict.keys())))
        # the answer is the string mapped to the question key
        answer = my_dict[question]

        # print the question, along with the question number
        print("\nQuestion " + str(i+1) )
        print(question  + "?")

        # get the user's answer attempt
        guess = input("> ")

        # if their guess is the same as the answer
        if guess.lower() == answer.lower():
            # add 1 to the score and print a message
            print("Correct!")
            score += 1
        else:
            print("Incorrect guess again!")

    # after the quiz, print their final score  
    print("\nYour final score was " + str(score))

    # store the user's input...
    again = input("Enter any key to play again, or 'q' to quit.")

    #... and quit if they types 'q'
    if again.lower() == 'q':
        playing = False

The code I'm struggling with in questions

Answer 1

num = re.match("r\\d[0-9]{2}$", num())

num is simply an interger, so num() is invalid.

Should be something like match = re.match("r\\d[0-9]{2}$", str(num))

1) it should be match right?

2) re is working on str , so the argument passed should be str(num)

Then the code should be fine and fun as well. :)