""" Purpose: introduce some another function from module random
"""

# by default the random module produces different interactions everytime we use it

import random
# whenever we want to use random, we have to import it and tell python where to find the functions

random.seed( 1112 ) # setting a seed means you should get the same results every run
# when you set the seed, you set it once before you start using choice() or randrange()
# the seed can be an integer, float, string, etc. the seed can be anything
# different data types will set the seed differently


# random function choice( seq ) when a given a sequence as a parameter returns
# a random element from the sequence

### get a string and choose four of its characters (repetition allowed)
s = input( "Enter a string: " )

ch1 = random.choice( s ) # tells python to go to the random module, find the choice() function, and run it using s as the
ch2 = random.choice( s ) # input
ch3 = random.choice( s ) # without setting a seed, we have no clue or control over what it will choose
ch4 = random.choice( s ) # the choice function chooses with replacement!! the same character can be pulled multiple times
# runs of choice() are independent and not reliant on previous choice() runs. it is possible to get the same value
# for ch1, ch2, ch3, and ch4, but it is not likely

# ** choice() will work on any sequence, you could have a list of anything and choice() will work

print ()

print( "Four random characters from string", s, ": ", ch1, ch2, ch3, ch4 )

print ()

### get a list of words and choose four (repetition allowed)
reply = input( "Enter some words: " )

user_words  = reply.split()

w1 = random.choice( user_words ) # same thing but looking at a list
w2 = random.choice( user_words )
w3 = random.choice( user_words )
w4 = random.choice( user_words )
# could also do this in a for loop!
# rand_words = []
# for i in range( 0, 4 ) :
#     w = random.choice( user_words )
#     rand_words.append( rand_words )

# nested loop - generate an image of random noise
# for r in range( 0, nrows ) :
#   for c in range( 0, ncols ):
#       pixel = random.choice( whatever )
#       probably more stuff but that's the gist

print( "Four random words from list", user_words, ":",  w1, w2, w3, w4 )

# choice() without replacement - there likely is a function in the random module to choose without replacement,
# or we could manually remove characters/words ourselves

# on homeworks, you will be given the sequences to pick from and the value to set as the seed using random.seed()
# with the seed, you will force the random generation to be non-random, allowing us to test your code
# you will have expected program runs and you will be expected to produce the same output with the seed
# if you don't use the seed() function, python will automatically use the current time to set as the seed

# how does the seed() work?
# random number generation comes from really weird kind of gross looking functions
# you start with a seed value, run it through the function a set number of times, and you get something random
# if we don't set the seed, it defaults to the time, meaning that each run is different
# every data structure is stored somewhere in your computer as a whole bunch of 1s and 0s

# "1112" is represented by a different string of 1s and 0s than 1112 is, so random.seed( '1112' ) and random.seed( 1112 )
# will produce a different set of random numbers, since they are different seeds