Hey guys i have a trouble when i want to add two binaries numbers in Python, i mean i can enter a chain of character in a form of a string but i don't know how to select a specific value in the chain. Here is my code:
chaina = input('Enter your first binary number')
chainb = input('Enter your second binary number')
liste = str()
r = 0
for i in range [-1,chaina]:
t = 0
t = chaina() + chainb() + r
if t == 2 :
r = 1
liste = str(t) + liste
elif t == 0 or t == 1:
r = 0
liste = str(t) + liste
To add two binary numbers chaina and chainb:
bin(eval('0b{} + 0b{}'.format(chaina, chainb)))
Or, if you want the binary number without the leading '0b':
format(eval('0b{} + 0b{}'.format(chaina, chainb)), 'b')
Explanation
Assume for illustration that chaina = '1010' and chainb = '1111'. Then:
>>> '0b{} + 0b{}'.format(chaina, chainb)
'0b1010 + 0b1111'
By applying eval() on this string, we get the same result as if we typed the expression 0b1010 + 0b1111 directly into Python console.
>>> 0b1010 + 0b1111
25
>>> eval('0b1010 + 0b1111')
25
Finally, bin() produces a binary representation of the number passed to it as an argument:
>>> bin(25)
'0b11001'
The same thing is accomplished by calling format() with a 'b' argument:
>>> format(25, 'b')
'11001'
All put together, we are getting the expressions shown above.
Why don't you simply convert them into decimal and add them as you would do with decimals:
y = '0b101010'
z = '0b101010'
print(int(y,2) + int(z,2))
print(bin((int(y,2) + int(z,2))))
Assuming that you want to do a binary sum by hand, you must:
process both numbers starting from the end (reversed will help here)
consistently add bits processing carry until the lengther of both numbers is exhausted
reorder the result bits (here again reversed)
Code could be (assuming that you can be sure that chaina and chainb only consist in 0 and 1 characters, no test for it here):
def binsum(chaina, chainb):
def next0(it):
"""Retrieve next digit from a binary representation, 0 when exhausted"""
try:
return int(next(it))
except StopIteration:
return 0
a = reversed(chaina) # reverse chains to start with lowest order bit
b = reversed(chainb)
r = 0
result = [] # future result
for i in range(n):
t = next0(a) + next0(b) + r # add with carry
if t > 1:
t -= 2
r = 1
else:
r = 0
result.append('1' if t else '0')
if r != 0: # do not forget last carry
result.append('1')
return ''.join(result)
A couple of suggestions
normalize the lengths of the bit strings
l0, l1 = map(len, (str0, str1))
if l0 < l1:
str0 = "0"*(l1-l0) + str0
elif l1 < l0:
str1 = "0"*(l0-l1) + str1
do a loop on the reversed strings elements and construct the binary string bottom up
remainder = 0
result = ""
for bit_0, bit1 in zip(reversed(str0), reversed(str1)):
bit_0, bit_1 = map(int, (bit_0, bit_1))
new_bit, remainder = f(bit_0, bit_1, remainder)
result = str(new_bit) + result
if remainder != 0
...
writing f(bit_0, bit_1, remainder) and treating what to do if remainder is not null at the end of the loop is left as an exercise.
Related
I find some difficulties with the task of printing numbers in given range that contain only odd digits.
f.e: The first number is 2345 and the second number is 6789. There is one more thing - the printed numbers should be limited only the range according to the digit position 2 to 6 (3,5), 3 to 7(3,5,7), 4 to 8(5,7), 5 to 9(5,7,9) - so it means that the first numbers should be 3355,3357,3359,3375,3377,3379,3555,3557....
The code does not execute it the way output should look:
number_one=int(input())
number_two=int(input())
list_one=[]
list_two=[]
number_one=str(number_one)
number_two=str(number_two)
for i in number_one:
if int(i)==0 or int(i)%2==0:
i=int(i)+1
list_one.append(int(i))
for i in number_two:
list_two.append(int(i))
a=0
b=0
c=0
d=0
for j in range(list_one[0],list_two[0]+1):
if j%2==1:
a=j
for p in range(list_one[1],list_two[1]+1):
if p%2==1:
b=p
for x in range(list_one[2],list_two[2]+1):
if x%2==1:
c=x
for y in range(list_one[3],list_two[3]+1):
if y%2==1:
d=y
print(f"{a}{b}{c}{d}",end=" ")
There are a lot of repetitions in the output that I would like to avoid.
Thank you in advance!
May be this is not an optimal solution.
But this is working for positive integers with same length.
number_one=int(input())
number_two=int(input())
if len(str(number_one)) != len(str(number_two)):
raise Exception("numbers should be of same length")
def print_num(num_one, num_two):
res = []
for i,j in zip(num_one, num_two):
next_odd_for_i = int(i) + (not (int(i)%2))
prev_odd_for_j = int(j) - (not (int(j)%2))
temp_str = ""
for i_next in range(next_odd_for_i, prev_odd_for_j+1, 2):
temp_str += str(i_next)
res.append(temp_str)
return res
def print_perm(li_of_str):
if len(li_of_str) == 1:
return [li_of_str[-1]]
res = []
first = li_of_str[0]
for j in first:
tmp = [j+k for n in print_perm(li_of_str[1:]) for k in n ]
res.append(tmp)
return res
print(print_num(str(number_one), str(number_two)))
print(print_perm(print_num(str(number_one), str(number_two))))
One way to solve this problem is with recursion. This function takes in two strings representing numbers and returns all the odd numbers (as strings) that satisfy the conditions you specified:
def odd_digits(num1, num2):
# split off first digit of string
msd1, rest1 = int(num1[0]), num1[1:]
# make the digit odd if required
msd1 += msd1 % 2 == 0
# split off first digit of string
msd2, rest2 = int(num2[0]), num2[1:]
# make the digit odd if required
msd2 -= msd2 % 2 == 0
# if no more digits, just return the values between msd1 and msd2
if not rest1:
return [str(i) for i in range(msd1, msd2+1, 2)]
# otherwise, append the results of a recursive call to each
# odd digit between msd1 and msd2
result = []
for i in range(msd1, msd2+1, 2):
result += [str(i) + o for o in odd_digits(rest1, rest2)]
return result
print(odd_digits('2345', '6789'))
Output:
[
'3355', '3357', '3359',
'3375', '3377', '3379',
'3555', '3557', '3559',
'3575', '3577', '3579',
'3755', '3757', '3759',
'3775', '3777', '3779',
'5355', '5357', '5359',
'5375', '5377', '5379',
'5555', '5557', '5559',
'5575', '5577', '5579',
'5755', '5757', '5759',
'5775', '5777', '5779'
]
If you want to use integer values just use (for example)
print(list(map(int, odd_digits(str(2345), str(6789)))))
The output will be as above but all values will be integers rather than strings.
If you can use libraries, you can generate ranges for each digit and then use itertools.product to find all the combinations:
import itertools
def odd_digits(num1, num2):
ranges = []
for d1, d2 in zip(num1, num2):
d1 = int(d1) + (int(d1) % 2 == 0)
d2 = int(d2) - (int(d2) % 2 == 0)
ranges.append(list(range(d1, d2+1, 2)))
return [''.join(map(str, t)) for t in itertools.product(*ranges)]
This function takes string inputs and produces string outputs, which will be the same as the first function above.
How to insert ' # ' for each n index from backward?
ex) n=4
evil = '01234567891234oooooooooooooooo321'
to
stan = '0#1234#5678#9123#4ooo#oooo#oooo#oooo#o321'
i tried using list with for,if statement, got stuck. something shameful like this
a = 1234567891234
b = [ a[-i] for i in range(1,len(a)+1)]
for i in range(len(b)):
c += b[i]
if i%4==0: #stuck
c += ','
c.reverse()
What is the optimum way?
You might use a pattern asserting optional repetitions of 4 characters to the right, and replace that position with #
import re
pattern = r"(?=(?:.{4})*$)"
s = "01234567891234oooooooooooooooo321"
print(re.sub(pattern, "#", s))
Output
0#1234#5678#9123#4ooo#oooo#oooo#oooo#o321#
Python demo
cut the string into chunks (backwards) and then concat them using the seperator
evil = '01234567891234oooooooooooooooo321'
l = 4
sep = '#'
sep.join([evil[max(i-l,0):i] for i in range(len(evil), 0, -l)][::-1])
'0#1234#5678#9123#4ooo#oooo#oooo#oooo#o321'
chunks function as in this answer
def chunks(lst, n):
"""Yield successive n-sized chunks from lst."""
for i in range(0, len(lst), n):
yield lst[i:i + n]
evil = '01234567891234oooooooooooooooo321'
n = 4
stan = "#".join(chunks(evil[::-1], n))[::-1]
print(stan) # Output: 0#1234#5678#9123#4ooo#oooo#oooo#oooo#o321
Input string is reversed ([::-1]), split into chunks, joined by "#" and then reversed back again. (It's possible to skip reverses if you calculate how many characters there will be in the first set of characters)
A naive solution would be using parts of evil string:
evil = '01234567891234oooooooooooooooo321'
n = 4
start = len(evil) % n
insert = '#'
stan = evil[:start] + insert
for i in range(start, len(evil) - n, n):
stan += evil[i:i+n] + insert
stan += evil[-n:]
For this, I would go backwards through your string evil by reversing the string and iterating through it in a for loop. Then I set a count variable to keep track of how many loops it's done, and reset to 0 when it equals 4. All of this looks like the below:
count = 0
for char in evil[::-1]:
if count == 4:
count = 0
count += 1
You can then establish a new empty string (new_str), and append each character of evil to, each time checking if count is 4, and adding a # to the string as well before resetting the count. Full code:
count = 0
new_str = ''
for char in evil[::-1]:
if count == 4:
new_str += '#'
count = 0
count += 1
new_str += char
This will produce the new string reversed, so you need to reverse it again to get the desired result:
new_str = new_str[::-1]
Output:
'123o#oooo#oooo#oooo#ooo4#3219#8765#4321#0'
You can do it like this:
evil = '01234567891234oooooooooooooooo321'
''.join(j if i%4 else f'#{j}' for i, j in enumerate(evil[::-1]))[::-1][:-1]
Output:
'0#1234#5678#9123#4ooo#oooo#oooo#oooo#o321'
An exact method: use divmod to get the reminder and quotient of the string when divided in "blocks" of size 4 then slice.
evil = '01234567891234oooooooooooooooo321'
size = 4
q, r = divmod(len(evil), size)
sep = '#'
stan = f"{evil[:r]}{sep}{sep.join(evil[r+i*size: r+(i+1)*size] for i in range(q))}"
print(stan)
Remark: if the length of the string is a multiple of the block's size the new string will start with sep. Assumed as default behavior since lake of explanation
I am trying to remake the built-in function for bin(x) for better understanding, I have got that part down, now the issue is how to dynamically remove the 0s when they are not necessary.
I have tried using replace() but it seems to be removing every suggested "0" I am unsure how to select the zeroes till it hits the first index in which there is a "1"
for eg:
if i have 0b00010010
___
0b00010010
^
I would like to select the numbers after the 0b and erase the 0s right after until "1"
def bin(x):
if x>0:
binary = ""
i = 0
while x>0 and i<=16:
string = str(int(x%2))
binary = binary+string
x/=2
i = i+1
d = binary[::-1]
ret = f"0b{d}"
return ret.replace("00","")
else:
x = abs(x)
binary = ""
i = 0
while x > 0 and i <=16:
string = str(int(x % 2))
binary = binary + string
x /= 2
i = i + 1
nd = binary[::-1]
ret = f"-0b{nd}"
return ret.replace("00","")
print(bin(8314))# 0b00010000001111010 this is the current out
0b00010000001111010 this is the current output
0b10000001111010 this is what I want
It might be better to simplify things by not generating those extra zeroes in the first place:
def bin(x):
prefix = ("-" if x < 0 else "")
x = abs(x)
bits = []
while x:
x, bit = divmod(x, 2) # division and remainder in one operation
bits.append(str(bit))
# Flip the bits so the LSB is on the right, then join as string
bit_string = ''.join(bits[::-1])
# Form the final string
return f"{prefix}0b{bit_string}"
print(bin(8314))
prints
0b10000001111010
You should take a look at lstrip():
>>> b = "00010000001111010"
>>> b.lstrip("0")
'10000001111010'
Of course, make sure to prefix the binary with "0b" after calling lstrip().
Scott Hunter brought up a nice solution to your problem, however, if you want to use a for loop, consider trying the following:
binary = "0b00010000001111010"
start_index = binary.find("b")
for index in range(b+1, len(binary)):
if binary[index] == 0:
binary = binary[0:index:] + binary[index+1::]
else:
break
I have a version number in a file like this:
Testing x.x.x.x
So I am grabbing it off like this:
import re
def increment(match):
# convert the four matches to integers
a,b,c,d = [int(x) for x in match.groups()]
# return the replacement string
return f'{a}.{b}.{c}.{d}'
lines = open('file.txt', 'r').readlines()
lines[3] = re.sub(r"\b(\d+)\.(\d+)\.(\d+)\.(\d+)\b", increment, lines[3])
I want to make it so if the last digit is a 9... then change it to 0 and then change the previous digit to a 1. So 1.1.1.9 changes to 1.1.2.0.
I did that by doing:
def increment(match):
# convert the four matches to integers
a,b,c,d = [int(x) for x in match.groups()]
# return the replacement string
if (d == 9):
return f'{a}.{b}.{c+1}.{0}'
elif (c == 9):
return f'{a}.{b+1}.{0}.{0}'
elif (b == 9):
return f'{a+1}.{0}.{0}.{0}'
Issue occurs when its 1.1.9.9 or 1.9.9.9. Where multiple digits need to rounded. How can I handle this issue?
Use integer addition?
def increment(match):
# convert the four matches to integers
a,b,c,d = [int(x) for x in match.groups()]
*a,b,c,d = [int(x) for x in str(a*1000 + b*100 + c*10 + d + 1)]
a = ''.join(map(str,a)) # fix for 2 digit 'a'
# return the replacement string
return f'{a}.{b}.{c}.{d}'
If your versions are never going to go beyond 10, it is better to just convert it to an integer, increment it and then convert back to a string.
This allows you to go up to as many version numbers as you require and you are not limited to thousands.
def increment(match):
match = match.replace('.', '')
match = int(match)
match += 1
match = str(match)
output = '.'.join(match)
return output
Add 1 to the last element. If it's more than 9, set it to 0 and do the same for the previous element. Repeat as necessary:
import re
def increment(match):
# convert the four matches to integers
g = [int(x) for x in match.groups()]
# increment, last one first
pos = len(g)-1
g[pos] += 1
while pos > 0:
if g[pos] > 9:
g[pos] = 0
pos -= 1
g[pos] += 1
else:
break
# return the replacement string
return '.'.join(str(x) for x in g)
print (re.sub(r"\b(\d+)\.(\d+)\.(\d+)\.(\d+)\b", increment, '1.8.9.9'))
print (re.sub(r"\b(\d+)\.(\d+)\.(\d+)\.(\d+)\b", increment, '1.9.9.9'))
print (re.sub(r"\b(\d+)\.(\d+)\.(\d+)\.(\d+)\b", increment, '9.9.9.9'))
Result:
1.9.0.0
2.0.0.0
10.0.0.0
I want to be able to generate 12 character long chain, of hexadecimal, BUT with no more than 2 identical numbers duplicate in the chain: 00 and not 000
Because, I know how to generate ALL possibilites, including 00000000000 to FFFFFFFFFFF, but I know that I won't use all those values, and because the size of the file generated with ALL possibilities is many GB long, I want to reduce the size by avoiding the not useful generated chains.
So my goal is to have results like 00A300BF8911 and not like 000300BF8911
Could you please help me to do so?
Many thanks in advance!
if you picked the same one twice, remove it from the choices for a round:
import random
hex_digits = set('0123456789ABCDEF')
result = ""
pick_from = hex_digits
for digit in range(12):
cur_digit = random.sample(hex_digits, 1)[0]
result += cur_digit
if result[-1] == cur_digit:
pick_from = hex_digits - set(cur_digit)
else:
pick_from = hex_digits
print(result)
Since the title mentions generators. Here's the above as a generator:
import random
hex_digits = set('0123456789ABCDEF')
def hexGen():
while True:
result = ""
pick_from = hex_digits
for digit in range(12):
cur_digit = random.sample(hex_digits, 1)[0]
result += cur_digit
if result[-1] == cur_digit:
pick_from = hex_digits - set(cur_digit)
else:
pick_from = hex_digits
yield result
my_hex_gen = hexGen()
counter = 0
for result in my_hex_gen:
print(result)
counter += 1
if counter > 10:
break
Results:
1ECC6A83EB14
D0897DE15E81
9C3E9028B0DE
CE74A2674AF0
9ECBD32C003D
0DF2E5DAC0FB
31C48E691C96
F33AAC2C2052
CD4CEDADD54D
40A329FF6E25
5F5D71F823A4
You could also change the while true loop to only produce a certain number of these based on a number passed into the function.
I interpret this question as, "I want to construct a rainbow table by iterating through all strings that have the following qualities. The string has a length of 12, contains only the characters 0-9 and A-F, and it never has the same character appearing three times in a row."
def iter_all_strings_without_triplicates(size, last_two_digits = (None, None)):
a,b = last_two_digits
if size == 0:
yield ""
else:
for c in "0123456789ABCDEF":
if a == b == c:
continue
else:
for rest in iter_all_strings_without_triplicates(size-1, (b,c)):
yield c + rest
for s in iter_all_strings_without_triplicates(12):
print(s)
Result:
001001001001
001001001002
001001001003
001001001004
001001001005
001001001006
001001001007
001001001008
001001001009
00100100100A
00100100100B
00100100100C
00100100100D
00100100100E
00100100100F
001001001010
001001001011
...
Note that there will be several hundred terabytes' worth of values outputted, so you aren't saving much room compared to just saving every single string, triplicates or not.
import string, random
source = string.hexdigits[:16]
result = ''
while len(result) < 12 :
idx = random.randint(0,len(source))
if len(result) < 3 or result[-1] != result[-2] or result[-1] != source[idx] :
result += source[idx]
You could extract a random sequence from a list of twice each hexadecimal digits:
digits = list('1234567890ABCDEF') * 2
random.shuffle(digits)
hex_number = ''.join(digits[:12])
If you wanted to allow shorter sequences, you could randomize that too, and left fill the blanks with zeros.
import random
digits = list('1234567890ABCDEF') * 2
random.shuffle(digits)
num_digits = random.randrange(3, 13)
hex_number = ''.join(['0'] * (12-num_digits)) + ''.join(digits[:num_digits])
print(hex_number)
You could use a generator iterating a window over the strings your current implementation yields. Sth. like (hex_str[i:i + 3] for i in range(len(hex_str) - window_size + 1)) Using len and set you could count the number of different characters in the slice. Although in your example it might be easier to just compare all 3 characters.
You can create an array from 0 to 255, and use random.sample with your list to get your list