Random numbers and alphabet mixture

[jumperbl]

Hi,

I am a noob and I was wondering if there is way to generate random mixture of alphabets and numbers? For example:

1234567890ABCDEFG
or
4BA92ABD293BC3890

the length needs to be 17 characters long.

[jlm699]

Hi,

I am a noob and I was wondering if there is way to generate random mixture of alphabets and numbers? For example:

1234567890ABCDEFG
or
4BA92ABD293BC3890

the length needs to be 17 characters long.

How about this list comprehension:

>>> ''.join([chr([random.randrange(48,58),random.randrange(65,91)][random.randint(0,1)]) for x in xrange(17)])
'3E4F8F756F584Z8XU'
 

Or in non-comprehension form:

import random
 
rstring = ''
for x in xrange(17):
    rint = random.randint(0,1)
    if rint:
        rstring += chr(random.randrange(48,58))
    else:
        rstring += chr(random.randrange(65,91))
 
>>> rstring
'T374TX07KEP031F17'
 

[bvdet]

Hi,

I am a noob and I was wondering if there is way to generate random mixture of alphabets and numbers? For example:

1234567890ABCDEFG
or
4BA92ABD293BC3890

the length needs to be 17 characters long.

That is easily done with the random.choice() function, a list or string of character choices, and a list comprehension or for loop. Select a character from the choices 17 times, and join or concatenate the characters. Try coding yourself and post back.

Example output from a variable characters, 10 random strings:

>>> characters
'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVW XYZ0123456789'
>>> j5jSeP4etag0EucN0
BAlxpfUfXnEjBNaL6
dB0GSaCFZMRg2DrqK
uMLz8ivN3cm8k8MCC
b6qHuPAf7ATYsLIjd
cfYmLEfGa66nKZzlJ
ldQd3ouLNSG7ghSu3
vxFn9UHchY8nRe2Mj
QfbuEMtfjRZJuxALZ
18TcORlqnZGrOUUrm
>>>

[bvdet]

Now that we have some code in this thread, I guess I'll post mine :)

>>> import random
>>> import string
>>> characters = string.letters+string.digits
>>> no_chrs = 17
>>> print ''.join([random.choice(characters) for _ in range(no_chrs)])
uGAGd5Er82VOFsjwh
>>> 

[jumperbl]

thanks guys for the help.

[jumperbl]

[quote=jlm699]How about this list comprehension:

>>> ''.join([chr([random.randrange(48,58),random.randrange(65,91)][random.randint(0,1)]) for x in xrange(17)])
'3E4F8F756F584Z8XU'
 

I am trying to understand this. So, you have a chr range of 0-9[48,58] and A-Z[65-91], but what is random.randint(0,1) is that step by one? I don't understand this. I like how this is written, but hopefully someone can explain.

[jlm699]

what is random.randint(0,1) is that step by one? I don't understand this.

No that is an obfuscated way to randomly choose between one of two choices.
Let's say you have a list tst = ['a', 'b']
Element 0 (tst[0]) is 'a' and element 1 (tst[1]) is 'b'. So let's say instead of storing the list to a variable tst you simply use the list itself:

>>> ['a', 'b'][0]
'a'
>>> ['a', 'b'][1]
'b'
 

Now if we put random.randint(0,1) in place of the index specifier, we have a randomly chosen element from the list picked

>>> import random
>>> ['a', 'b'][random.randint(0,1)]
'b'
>>> ['a', 'b'][random.randint(0,1)]
'a'
>>> 

So in my code example I have the random letter and the random number pickers contained in a ad-hoc list [random_letter, random_number] and an element is chosen based on the result of randint(0,1). Does that clear it up a little bit? Unfortunately, this is not the best practice in terms of computing efficiency as a random letter and two random numbers are generated on each iteration (actually three random numbers), whereas bvdet's solution only requires one random number (index of list) to be generated.

[bvdet]

How about this list comprehension:

>>> ''.join([chr([random.randrange(48,58),random.randrange(65,91)][random.randint(0,1)]) for x in xrange(17)])
'3E4F8F756F584Z8XU'
 

I am trying to understand this. So, you have a chr range of 0-9[48,58] and A-Z[65-91], but what is random.randint(0,1) is that step by one? I don't understand this. I like how this is written, but hopefully someone can explain.

Breaking it up into two parts:

>>> (chr(random.randrange(48,58)),chr(random.randrange(65,91)))
('6', 'O')
>>> (chr(random.randrange(48,58)),chr(random.randrange(65,91)))
('8', 'Y')
>>> random.randint(0,1)
 
>>> random.randint(0,1)
1
>>> (chr(random.randrange(48,58)),chr(random.randrange(65,91)))[random.randint(0,1)]
'T'
>>> (chr(random.randrange(48,58)),chr(random.randrange(65,91)))[random.randint(0,1)]
'R'
>>> (chr(random.randrange(48,58)),chr(random.randrange(65,91)))[random.randint(0,1)]
'3'
>>> 

#1 - Create a tuple containing a letter and a number
#2 - Take a slice of the tuple (using random.randint(0,1)) to produce a random letter or number

[jumperbl]

Thanks that helps. Makes sense now.

No that is an obfuscated way to randomly choose between one of two choices.
Let's say you have a list tst = ['a', 'b']
Element 0 (tst[0]) is 'a' and element 1 (tst[1]) is 'b'. So let's say instead of storing the list to a variable tst you simply use the list itself:

>>> ['a', 'b'][0]
'a'
>>> ['a', 'b'][1]
'b'
 

Now if we put random.randint(0,1) in place of the index specifier, we have a randomly chosen element from the list picked

>>> import random
>>> ['a', 'b'][random.randint(0,1)]
'b'
>>> ['a', 'b'][random.randint(0,1)]
'a'
>>> 

So in my code example I have the random letter and the random number pickers contained in a ad-hoc list [random_letter, random_number] and an element is chosen based on the result of randint(0,1). Does that clear it up a little bit? Unfortunately, this is not the best practice in terms of computing efficiency as a random letter and two random numbers are generated on each iteration (actually three random numbers), whereas bvdet's solution only requires one random number (index of list) to be generated.