I'm trying to modify the code to ignore white spaces in a Palindrome String. For example, the code should mark Do Geese See God as Palindrome. I've been trying to use .replace(" ", ""), but either an error pops up or the Palindrome is returned as False.
stk = Stack()
for i in range(len(sentence)):
stk.push(sentence[i])
for i in range(stk.size()):
stk.replace(" ","")
if sentence[i] != stk.pop():
return False;
return True;
I'm trying to not use stk.item[-1] or stk.item == stk.item[::-1] in Stack, by the way.
I would recommend just stripping all whitespace with a RegEx:
input = " A man a plan a canal Panama "
input = re.sub(r'\s+', '', input)
This would also handle the cases of leading and trailing whitespace, which you probably also want to ignore.
It may be a cut and paste error but you don't actually have a space in what you are replacing.
stk.replace(' ', '')
I've modified the code to make this work:
def isPalindrome(sentence):
sentence = sentence.replace (' '. '')
stk = Stack()
for i in range(len(sentence)):
stk.push(sentence[i])
for i in range(stk.size()):
stk.replace(' ','')
if sentence[i] != stk.pop():
return False;
return True;
Related
Unclear on how to frame the following function correctly:
Creating a function that will take in a string and return the string in camel case without spaces (or pascal case if the first letter was already capital), removing special characters
text = "This-is_my_test_string,to-capitalize"
def to_camel_case(text):
# Return 1st letter of text + all letters after
return text[:1] + text.title()[1:].replace(i" ") if not i.isdigit()
# Output should be "ThisIsMyTestStringToCapitalize"
the "if" statement at the end isn't working out, and I wrote this somewhat experimentally, but with a syntax fix, could the logic work?
Providing the input string does not contain any spaces then you could do this:
from re import sub
def to_camel_case(text, pascal=False):
r = sub(r'[^a-zA-Z0-9]', ' ', text).title().replace(' ', '')
return r if pascal else r[0].lower() + r[1:]
ts = 'This-is_my_test_string,to-capitalize'
print(to_camel_case(ts, pascal=True))
print(to_camel_case(ts))
Output:
ThisIsMyTestStringToCapitalize
thisIsMyTestStringToCapitalize
Here is a short solution using regex. First it uses title() as you did, then the regex finds non-alphanumeric-characters and removes them, and finally we take the first character to handle pascal / camel case.
import re
def to_camel_case(s):
s1 = re.sub('[^a-zA-Z0-9]+', '', s.title())
return s[0] + s1[1:]
text = "this-is2_my_test_string,to-capitalize"
print(to_camel_case(text)) # ThisIsMyTestStringToCapitalize
The below should work for your example.
Splitting apart your example by anything that isn's alphanumeric or a space. Then capitalizing each word. Finally, returning the re-joined string.
import re
def to_camel_case(text):
words = re.split(r'[^a-zA-Z0-9\s]', text)
return "".join([word.capitalize() for word in words])
text_to_camelcase = "This-is_my_test_string,to-capitalize"
print(to_camel_case(text_to_camelcase))
use the split function to split between anything that is not a letter or a whitespace and the function .capitalize() to capitalize single words
import re
text_to_camelcase = "This-is_my_test_string,to-capitalize"
def to_camel_case(text):
split_text = re.split(r'[^a-zA-Z0-9\s]', text)
cap_string = ''
for word in split_text:
cap_word = word.capitalize()
cap_string += cap_word
return cap_string
print(to_camel_case(text_to_camelcase))
I am trying to write a function to remove all punctuation characters from a string. I've tried several permutations on translate, replace, strip, etc. My latest attempt uses a brute force approach:
def clean_lower(sample):
punct = list(string.punctuation)
for c in punct:
sample.replace(c, ' ')
return sample.split()
That gets rid of almost all of the punctuation but I'm left with // in front of one of the words. I can't seem to find any way to remove it. I've even tried explicitly replacing it with sample.replace('//', ' ').
What do I need to do?
using translate is the fastest way to remove punctuations, this will remove // too:
import string
s = "This is! a string, with. punctuations? //"
def clean_lower(s):
return s.translate(str.maketrans('', '', string.punctuation))
s = clean_lower(s)
print(s)
Use regular expressions
import re
def clean_lower(s):
return(re.sub(r'\W','',s))
Above function erases any symbols except underscore
Perhaps you should approach it from the perspective of what you want to keep:
For example:
import string
toKeep = set(string.ascii_letters + string.digits + " ")
toRemove = set(string.printable) - toKeep
cleanUp = str.maketrans('', '', "".join(toRemove))
usage:
s = "Hello! world of / and dice".translate(cleanUp)
# s will be 'Hello world of and dice'
as suggested by #jasonharper you need to redefine "sample" and it should work:
import string
sample='// Hello?) // World!'
print(sample)
punct=list(string.punctuation)
for c in punct:
sample=sample.replace(c,'')
print(sample.split())
I'm creating a palindrome checker and it works however I need to find a way to replace/remove punctuation from the given input. I'm trying to do for chr(i) i in range 32,47 then substitute those in with ''. The characters I need excluded are 32 - 47. I've tried using the String module but I can only get it to either exclude spaces or punctuation it can't be both for whatever reason.
I've already tried the string module but can't get that to remove spaces and punctuation at the same time.
def is_palindrome_stack(string):
s = ArrayStack()
for character in string:
s.push(character)
reversed_string = ''
while not s.is_empty():
reversed_string = reversed_string + s.pop()
if string == reversed_string:
return True
else:
return False
def remove_punctuation(text):
return text.replace(" ",'')
exclude = set(string.punctuation)
return ''.join(ch for ch in text if ch not in exclude)
That is because you are returning from your method in the very first line, in return text.replace(" ",''). Change it to text = text.replace(" ", "") and it should work fine.
Also, the indentation is probably messed up in your post, maybe during copy pasting.
Full method snippet:
def remove_punctuation(text):
text = text.replace(" ",'')
exclude = set(string.punctuation)
return ''.join(ch for ch in text if ch not in exclude)
You might use str methods to get rid of unwanted characters following way:
import string
tr = ''.maketrans('','',' '+string.punctuation)
def remove_punctuation(text):
return text.translate(tr)
txt = 'Point.Space Question?'
output = remove_punctuation(txt)
print(output)
Output:
PointSpaceQuestion
maketrans create replacement table, it accepts 3 str-s: first and second must be equal length, n-th character from first will be replaced with n-th character from second, third str is characters to remove. You need only to remove (not replace) characters so first two arguments are empty strs.
How can I know if
word = " a "
has a whitespace around it (which it does here, but word is dynamic) and then, iff it does, then strip() it?
There is no point in checking before stripping. Just use str.strip(); it is safe to do so if there is no whitespace around the text:
word.strip()
If you really need to test, you could use str.startswith() and str.endswith() with tuples:
whitespace = tuple(' \n\r\t')
word.startswith(whitespace) or word.endswith(whitespace)
is true if there is whitespace at the start or end.
Can you not just strip() all words, will you not get the same result?
Compare the length before and after?
word = " a "
stripped = word.strip()
if len(word) != len(stripped):
return stripped
else:
return word
That may sound pretty silly, but as you're talking about only one space, why not do like this:
>>> a=" a "
>>> a[0]==' ' and a[-1]==' '
True
And then
if a and a[0]==' ' and a[-1]==' ':
#do the stuff you want to do
I would look into the startswith and endswith methods:
http://www.tutorialspoint.com/python/string_startswith.htm
http://www.tutorialspoint.com/python/string_endswith.htm
if word.startswith(' ') and word.endswith(' ') then
...
I have to write a code to do 2 things:
Compress more than one occurrence of the space character into one.
Add a space after a period, if there isn't one.
For example:
input> This is weird.Indeed
output>This is weird. Indeed.
This is the code I wrote:
def correction(string):
list=[]
for i in string:
if i!=" ":
list.append(i)
elif i==" ":
k=i+1
if k==" ":
k=""
list.append(i)
s=' '.join(list)
return s
strn=input("Enter the string: ").split()
print (correction(strn))
This code takes any input by the user and removes all the extra spaces,but it's not adding the space after the period(I know why not,because of the split function it's taking the period and the next word with it as one word, I just can't figure how to fix it)
This is a code I found online:
import re
def correction2(string):
corstr = re.sub('\ +',' ',string)
final = re.sub('\.','. ',corstr)
return final
strn= ("This is as .Indeed")
print (correction2(strn))
The problem with this code is I can't take any input from the user. It is predefined in the program.
So can anyone suggest how to improve any of the two codes to do both the functions on ANY input by the user?
Is this what you desire?
import re
def corr(s):
return re.sub(r'\.(?! )', '. ', re.sub(r' +', ' ', s))
s = input("> ")
print(corr(s))
I've changed the regex to a lookahead pattern, take a look here.
Edit: explain Regex as requested in comment
re.sub() takes (at least) three arguments: The Regex search pattern, the replacement the matched pattern should be replaced with, and the string in which the replacement should be done.
What I'm doing here is two steps at once, I've been using the output of one function as input of another.
First, the inner re.sub(r' +', ' ', s) searches for multiple spaces (r' +') in s to replace them with single spaces. Then the outer re.sub(r'\.(?! )', '. ', ...) looks for periods without following space character to replace them with '. '. I'm using a negative lookahead pattern to match only sections, that don't match the specified lookahead pattern (a normal space character in this case). You may want to play around with this pattern, this may help understanding it better.
The r string prefix changes the string to a raw string where backslash-escaping is disabled. Unnecessary in this case, but it's a habit of mine to use raw strings with regular expressions.
For a more basic answer, without regex:
>>> def remove_doublespace(string):
... if ' ' not in string:
... return string
... return remove_doublespace(string.replace(' ',' '))
...
>>> remove_doublespace('hi there how are you.i am fine. '.replace('.', '. '))
'hi there how are you. i am fine. '
You try the following code:
>>> s = 'This is weird.Indeed'
>>> def correction(s):
res = re.sub('\s+$', '', re.sub('\s+', ' ', re.sub('\.', '. ', s)))
if res[-1] != '.':
res += '.'
return res
>>> print correction(s)
This is weird. Indeed.
>>> s=raw_input()
hee ss.dk
>>> s
'hee ss.dk'
>>> correction(s)
'hee ss. dk.'