I'm trying to make a program that combines two words together in python.
For example, if I am combining "hello" and "chadd" it will return "hcehlaldod" by alternating letters.
Heres my code:
string1 = "hey"
string2 = "hii"
len1 = len(str(string1))
len2 = len(str(string2))
x = 0
final = ""
while (x <= len1):
final = final + string1[x] + string2[x]
x = x + 1
any help?
There is a simplest way of to do that like this:
string1 = "hey"
string2 = "hii"
new_str = ""
for char1,char2 in zip(string1, string2):
new_str += char1 + char2
if __name__ == '__main__':
print(new_str)
Change while (x <= len1) to while (x < len1) if you only care about the length of the first string.
If you care about the length of both strings, do while (x < len1 and x < len2) instead.
Your immediate problem with your loop is because you're using the condition while (x <= len1):
Let me explain. The length of your string is 3. The characters (and their indexes) are as follows:
0 1 2
h e y
You will see your string ends at index position 2. So now go back to your condition. You have set it to continue looping while (x <= len1):. So your loop will operate when x=0, x=1, x=2 and x=3. The x=3 is out of bounds since the indexes for your string end at index position 2.
What you should use is while (x < len1): which will stop at the correct point in your string.
You can pay attention to the lengths, as others have suggested, but you can also take a more functional approach with the built in zip function:
string1 = "hello"
string2 = "chadd"
string3 = ''.join(t[0] + t[1] for t in zip(string1, string2)) # hcehlaldod
zip works by pairing it's inputs:
print(list(zip(string1, string2))) # note that you should turn it into a list to print it
# [('h', 'c'), ('e', 'h'), ('l', 'a'), ('l', 'd'), ('o', 'd')]
And you can then just combine those into a string (like my first code snippit does).
Related
Hello I have to reorder a string, I am banned from using other types and str methods
So my problem is that I could not figure out how to end my code to get it work with any string
I tried to compare the results with sorted() to check and I am stuck at the first exchange
My code:
i = 0
s1 = "hello"
s2 = sorted(s1)
while (i<len(s1)):
j=i+1
while (j<=len(s1)-1):
if (s1[i] > s1[j]):
s1 = s1[0:i] + s1[j] + s1[i]
j+=1
i+=1
print(s1)
print(s2)
I tried to add + s1[len(s1):] at the end of the operation but
I only had found the result for a single string(that I was testing) adding thisI am really stuck, how can I make it work for all the strings with different lenghts??
Thanks
You're not reconstructing the string correctly when doing s1 = s1[0:i] + s1[j] + s1[i] as you're replacing one character for the other but you omit to actually interchange the two and to add the remains of the splitted string to the end of the new string.
Given what your code looks like, I would do it like this:
i = 0
s1 = "hello"
s2 = sorted(s1)
while i < len(s1):
j = i + 1
while j <= len(s1)-1:
if s1[i] > s1[j]:
s1 = s1[0:i] + s1[j] + s1[i+1:j] + s1[i] + s1[j+1:len(s1)]
j += 1
i += 1
print("".join(s2))
# > 'ehllo'
print(s1)
# > 'ehllo'
Please tell me if anything is unclear!
I am banned from using other types and str methods
Based upon your criteria, your request is impossible. Just accessing the elements of a string requires string methods.
The technique that you are using is very convoluted, hard to read and is difficult to debug. Try running your code in a debugger.
Now given that you are allowed to convert a string to a list (which requires string methods), redesign your code to use simple, easy to understand statements.
The following code first converts the string into a list. Then loops thru the list starting at the beginning and compares each following character to the end. If any character is less then the current character, swap. As you step thru the string, the character swaps will result in a sorted list. At the end convert the list back to a string using join().
msg = 'hello'
s = list(msg)
for i in range(len(s) - 1):
for j in range(i + 1, len(s)):
if s[i] <= s[j]:
continue
# swap characters
s[i], s[j] = s[j], s[i]
print(msg)
print(''.join(s))
Lets say with a string = "AABBAAAAABBBBAAABBBBAA"
I want to return string split by the odd lengths of the string (i.e when A = 5 or A = 3),
What I want returned is 1) AABBAAAAA 2)BBBBAAA 3)BBBBAA,
How can I do that?
I tried using regex [A]+[B]+ for a slightly different case
One option might be to regex iterate using re.finditer with the following pattern:
.*?(?:AAA(?:AA)?|$)
This pattern will non greedily consume until reaching either 3 A's, 5 A's, or the end of the string. Then, we can print out each complete match as we iterate.
input = 'AABBAAAAABBBBAAABBBBAA'
pattern = '.*?(?:AAA(?:AA)?|$)'
for match in re.finditer(pattern, input):
print match.group()
This prints:
AABBAAAAA
BBBBAAA
BBBBAA
You can use itertools.groupby:
s = 'BBAAAAABBBBAAABBBBAA'
from itertools import groupby
out = ['']
for v, g in groupby(s):
l = [*g]
out[-1] += ''.join(l)
if v == 'A' and len(l) in (3, 5):
out.append('')
print(out)
Prints:
['BBAAAAA', 'BBBBAAA', 'BBBBAA']
How would i split a string into sub array's of n length in Matlab?
eg.
Input: "ABCDEFGHIJKL", with sub arrays of length 3
Output: {ABC}, {DEF}, {GHI}, {JKL}
If the string length is not a multiple of n you probably need a loop or arrayfun:
x = 'ABCDEFGHIJK'; % length 11
n = 3;
result = arrayfun(#(k) x(k:min(k+n-1, end)), 1:n:numel(x), 'UniformOutput', false)
Alternatively, accumarray can be used as well:
x = 'ABCDEFGHIJK';
n = 3;
result = accumarray(floor((0:numel(x)-1).'/n)+1, x, [], #(t) {t.'}).';
Either of the above gives, in this example,
result =
1×4 cell array
{'ABC'} {'DEF'} {'GHI'} {'JK'}
A regular expression can do the job here:
str = 'abcdefgh'
exp = '.{1,3}' %the regular expression (get all the group of 3 char, if number of char left < 3, take the rest)
res = regexp(str,exp,'match')
which give:
res =
1×3 cell array
{'abc'} {'def'} {'gh'}
If you only want to match group of 3 char:
exp = '.{3}' %this will output {'abc'} {'def'} but no {'gh'}
This shoud do it :)
string = cellstr(reshape(string, 3, [])')
How can I shuffle two strings s||t (shuffle(s, t)) with the given requirement that the first char always stands in front of the second one in s and t as well no matter we shuffle. The result returns as a set of strings without duplicates.
I have the following test:
print(shuffle('ab', 'cd'))
Result:
['abcd', 'acbd', 'acdb', 'cabd', 'cadb', 'cdab']
Thanks a lot.
This method will shuffle two strings and return a list of shuffles between them where the order of the characters is the same as in the original strings. If there are duplicate characters there will be duplicate results as well.
def shuffle(s1, s2):
if len(s1) == 1:
return [s2[:i] + s1 + s2[i:] for i in range(len(s2) + 1)]
if len(s2) == 1:
return [s1[:i] + s2 + s1[i:] for i in range(len(s1) + 1)]
return [s1[0]+ s for s in shuffle(s1[1:], s2)] + [s2[0] + s for s in shuffle(s1, s2[1:])]
print shuffle("ab", "cd")
It works by getting the first character of each string and recursively shuffling the rest and adding this character to each element in the list. When there is one character remaining on each of the strings it returns a list where the character is added in each position of the other string. Hope it helps.
So you can apply a condition on final shuffled list to generate a new list from the shuffled one:
S=shuffle('ab','cd')
nl=[]
for w in S:
if(w.index('a')<w.index('b') and w.index('c')<w.index('d')):
nl.append(w)
So nl is your new list as per your requirement:)
If I understood the question correctly, this should work. Note, as you add letters to this, it becomes a long running problem. 4 letters have 6 possible combination for each entry in the list. 8 letters have 5,040 possible combinations for each entry in the list.
import random
import math
InputList = ['ab','cd']
PossibleUniqueCombinations = math.factorial(len("".join(InputList))-1)
print (PossibleUniqueCombinations)
TargetList = []
UniqueCombinationList = []
for lst in InputList:
UniqueCnt = 0
FirstChar = lst[0]
TheRest = list(lst[1:])
while UniqueCnt < PossibleUniqueCombinations:
if InputList.index(lst) == 0:
LeftList = []
else:
LeftList = InputList[0:InputList.index(lst)]
RightList = list(InputList[InputList.index(lst)+1:])
TargetList = LeftList + TheRest + RightList
TargetStr = ''.join(TargetList)
TargetStr = ''.join(random.sample(TargetStr, len(TargetStr)))
ShuffledStr = FirstChar + ''.join(TargetStr)
try:
FndIdx = UniqueCombinationList.index(ShuffledStr)
except ValueError:
UniqueCombinationList.append(ShuffledStr)
UniqueCnt += 1
for combo in UniqueCombinationList:
print(combo)
Hello this function should take a String and return a list of Strings split at the Char c. I should define some helper functions but currently the user must initialize args that should be hidden from them.
xs = output list, i = start index for substr, j = end index for substr
example: split "123,456,789" ',' [] 0 0
should yield ["789", "456", "123"]
split s c xs i j =
if j == length s
then (subStr s i j) : xs
else if head (drop j s) == c
then split s c (subStr s i j : xs) (j + 1) (j + 1)
else split s c xs i (j + 1)
subStr s i j = take j(drop i s)
When i apply the function with the following args: split "123,456,789" ',' [] 0 0
I'm getting the result: ["789", "456,789", "123"]
I already mentioned this on your other post, but the issue with this is your subStr function. If you change it to subStr s i j = take (j-i) (drop i s) it should work. And if that's all you want, great. But it could be written more clearly and easily using takeWhile, or using split from data.Text.
Also, type signatures please. (Although I do appreciate that you defined the inputs this time.) Not only do they make it easier for us to help, you can often solve your own problems in the process of figuring them out.