Is there anyway to use less if statements in my function?

I have made a random password generator using a class called password and a method called generate.

My program works as it should. It generates a random password determined by the users preferences for length, upper or lowercase, numbers and special characters.

I was just wondering if there was a way to refactor the numerous if statements I have used to determine what sort of password the program would generate.

Any other suggestions for improvements I could make would also be helpful. Thanks a ton :D

Code:

import random
import string

class password:
    def __init__(self, length, string_method, numbers=True, special_chars=False):
        self.length = length
        self.string_method = string_method
        self.numbers = numbers
        self.special_chars = special_chars

    def generate(self, iterations):

        # Checking what type of string method the user has asked for

        if self.string_method == 'upper':
            stringMethod = string.ascii_uppercase
        elif self.string_method == 'lower':
            stringMethod = string.ascii_lowercase
        elif self.string_method == 'both':
            stringMethod = string.ascii_letters

        # Checking if the user has asked for numbers or not

        if self.numbers == True:
            stringNumbers = string.digits
        elif self.numbers == False:
            stringNumbers = ''

        # Checking if the user has asked for special characters or not

        if self.special_chars == True:
            stringSpecial = string.punctuation
        elif self.special_chars == False:
            stringSpecial = ''

        characters = stringMethod + stringNumbers + stringSpecial

        # Generating the password

        for p in range(iterations):
            output_password = ''
            for c in range(self.length):
                output_password += random.choice(characters)
            print(output_password)

# Test

password1 = password(20, 'lower', True, False) # password length = 20, string method is lowercase, numbers are true and special characters are false
password1.generate(3) # generate the random password 3 times```

Answer

Evaluate it in the initializer. It’s not less if checks per se, but it’s a bit cleaner.

import random
import string

class Password:
    def __init__(self, length, string_method, numbers=True, special_chars=False):
        self.length = length
        self.string_method = {
            'upper': string.ascii_uppercase,
            'lower': string.ascii_lowercase,
            'both':  string.ascii_letters
        }[string_method]
        self.numbers = string.digits if numbers else ''
        self.special_chars = string.punctuation if special_chars else ''

    def generate(self, iterations):
        characters = self.string_method + self.numbers + self.special_chars

        # Generating the password
        for p in range(iterations):
            output_password = ''
            for c in range(self.length):
                output_password += random.choice(characters)
            print(output_password)

# Test

password = Password(20, 'lower', True, False)
password.generate(3) # generate the random password 3 times

If you actually want less checks, then just pass in the characters directly.

import random
import string

class Password:
    def __init__(self, length, characters):
        self.length = length
        self.characters = characters

    def generate(self, iterations):
        # Generating the password    
        for p in range(iterations):
            output_password = ''
            for c in range(self.length):
                output_password += random.choice(self.characters)
            print(output_password)

# Test

password = Password(20, string.ascii_lowercase + string.digits)
password.generate(3) # generate the random password 3 times