Making the random.randint(a,b) change everytime when using a while loop?-CodePudding

In the code that I'm writing, I have a nested dictionary which contains a key that has a value of random.randint(0,100). Below this code is a while loop that contains functions which need the items from the dictionary.

When the while loop runs again, the random.randint(0,100) outputs the same value. How do I make it so the random value is different? I tried making a new .py file and placing the random.randint(a,b) under variables in a While true loop, but the code in the main file never starts. I couldn't put the dictionary inside of the while loop or after it ended because then the code wouldn't work.

For reference, this is what the code looks like (making a summary of it because the original code is too long to paste):

A = {'Key1': {'Key A1': 1, 'Key B1': 5, 'Random': random.randint(0,100)},
     'Key2': {'Key A2': 4, 'Key B2': 7, 'Random': random.randint(5,100)}
     'Key3': {'Key A3': 5, 'Key B3': 13, 'Random': random.randint(5,90)}}
while I > 5:
    def func(a,b):
        Rand_Value = A['Key1']['Random']
        print(f'The value for this is {Rand_Value}')
    func(10,5)

I'm new to coding, my apologies if the question is not as good as it could be.

CodePudding user response：

The problem is, that your dictionary gets populated with random values only once. The method random.randint(0, 100) will return a random value once and not every time you make use of your dictionary, eg.:

A = {'Key1': {'Key A1': 1, 'Key B1': 5, 'Random': random.randint(0,100)},
     'Key2': {'Key A2': 4, 'Key B2': 7, 'Random': random.randint(5,100)}
     'Key3': {'Key A3': 5, 'Key B3': 13, 'Random': random.randint(5,90)}}

might become

A = {'Key1': {'Key A1': 1, 'Key B1': 5, 'Random': 7},
     'Key2': {'Key A2': 4, 'Key B2': 7, 'Random': 18}
     'Key3': {'Key A3': 5, 'Key B3': 13, 'Random': 96}}

As you can see the random values are now fixed and won't change ever again.

To solve the problem you could create a function to re-initialize your dictionary each time you make use of it, like I did down below.

def initialize_dictionary():
    return {
            'Key1': {'Key A1': 1, 'Key B1': 5, 'Random': random.randint(0,100)},
            'Key2': {'Key A2': 4, 'Key B2': 7, 'Random': random.randint(5,100)},
            'Key3': {'Key A3': 5, 'Key B3': 13, 'Random': random.randint(5,90)}
        }

# do stuff
while i < 5:
    def func(a, b):
        my_new_dict = initialize_dictionary() # will create a new dict with new random values
        Rand_Value = my_new_dict['Key1']['Random']
        print(f'The value for this is {Rand_Value}')
    func(10, 5)

Nevertheless I would recommend you to use something like the following, because the above solution can result into very slow performance speed, if you have a huge dictionary, which needs to be re-initialized over and over again.

# do stuff
while i < 5:
    def func(a, b):
        Random_Value = random.randint(0, 100)
        print(f'The value for this is {Rand_Value}')
    func(10, 5)

Tip: You could add two key-value pairs in your dictionary, which will give you the starting and end value of your range, if you need different ranges for each key.

A = {'Key1': {'Key A1': 1, 'Key B1': 5, 'start': 0, 'end': 100},
     'Key2': {'Key A2': 4, 'Key B2': 7, 'start': 5, 'end': 100}
     'Key3': {'Key A3': 5, 'Key B3': 13, 'start': 5, 'end': 90}}

start = A['Key1']['start']
end = A['Key1']['end']
Random_Value = random.randint(start, end)

CodePudding user response：

if putting random function in the dictionary is necessarily you can do it with lambda like this (do not forget to call it):

from random import randint

A = {'Key1': {'Key A1': 1, 'Key B1': 5, 'Random': lambda : randint(0,100)},
     'Key2': {'Key A2': 4, 'Key B2': 7, 'Random': lambda : randint(5,100)},
     'Key3': {'Key A3': 5, 'Key B3': 13, 'Random': lambda : randint(5,90)}}

res = [A['Key1']['Random']() for _ in range(5)]
#-------------------------^^ calling lambda
print(res)
'''
[59, 66, 42, 79, 100]

but the better solution would be replacing random function with it parameters in the dictionary (do not forget to unpack):

from random import randint

A = {'Key1': {'Key A1': 1, 'Key B1': 5, 'Random': (0,100)},
     'Key2': {'Key A2': 4, 'Key B2': 7, 'Random': (5,100)},
     'Key3': {'Key A3': 5, 'Key B3': 13, 'Random': (5,90)}}

res = [randint(*A['Key1']['Random']) for _ in range(5)]
#--------------^ unpacking
print(res)
'''
[8, 65, 10, 67, 76]