How would I separate characters once I have a string of unseparated words?
For example to translate "take the last character of the suffix and add a space to it every time ("aSuffixbSuffixcSuffix" --> "aSuffix bSuffix cSuffix").`
Or, more generally, to replace the x-nth character, where x is any integer (e.g., to replace the 3rd, 6th, 9th, etc. character some something I choose).
Assuming you're getting your string from this question, the easiest way is to not cram all the strings together in the first place. Your original create_word could be changed to this:
def create_word(suffix):
letters="abcdefghijklmnopqrstuvwxyz"
return [i + suffix for i in letters]
Then you'd be able to take e and ''.join(e) or ' '.join(e) to get the strings you want.
str = "SuffixbSuffixcSuffix"
def chunk_str(str, chunk_size):
return [str[i:i+chunk_size] for i in range(0, len(str), chunk_size)]
" ".join(chunk_str(str,3))
returns:
'Suf fix bSu ffi xcS uff ix'
You could use the replace method of strings. Check the documentation
initial = "aSuffixbSuffixcSuffix"
final = initial.replace("Suffix", "Suffix ")
print(final)
Related
There is a string, for example. EXAMPLE.
How can I remove the middle character, i.e., M from it? I don't need the code. I want to know:
Do strings in Python end in any special character?
Which is a better way - shifting everything right to left starting from the middle character OR creation of a new string and not copying the middle character?
In Python, strings are immutable, so you have to create a new string. You have a few options of how to create the new string. If you want to remove the 'M' wherever it appears:
newstr = oldstr.replace("M", "")
If you want to remove the central character:
midlen = len(oldstr) // 2
newstr = oldstr[:midlen] + oldstr[midlen+1:]
You asked if strings end with a special character. No, you are thinking like a C programmer. In Python, strings are stored with their length, so any byte value, including \0, can appear in a string.
To replace a specific position:
s = s[:pos] + s[(pos+1):]
To replace a specific character:
s = s.replace('M','')
This is probably the best way:
original = "EXAMPLE"
removed = original.replace("M", "")
Don't worry about shifting characters and such. Most Python code takes place on a much higher level of abstraction.
Strings are immutable. But you can convert them to a list, which is mutable, and then convert the list back to a string after you've changed it.
s = "this is a string"
l = list(s) # convert to list
l[1] = "" # "delete" letter h (the item actually still exists but is empty)
l[1:2] = [] # really delete letter h (the item is actually removed from the list)
del(l[1]) # another way to delete it
p = l.index("a") # find position of the letter "a"
del(l[p]) # delete it
s = "".join(l) # convert back to string
You can also create a new string, as others have shown, by taking everything except the character you want from the existing string.
How can I remove the middle character, i.e., M from it?
You can't, because strings in Python are immutable.
Do strings in Python end in any special character?
No. They are similar to lists of characters; the length of the list defines the length of the string, and no character acts as a terminator.
Which is a better way - shifting everything right to left starting from the middle character OR creation of a new string and not copying the middle character?
You cannot modify the existing string, so you must create a new one containing everything except the middle character.
Use the translate() method:
>>> s = 'EXAMPLE'
>>> s.translate(None, 'M')
'EXAPLE'
def kill_char(string, n): # n = position of which character you want to remove
begin = string[:n] # from beginning to n (n not included)
end = string[n+1:] # n+1 through end of string
return begin + end
print kill_char("EXAMPLE", 3) # "M" removed
I have seen this somewhere here.
card = random.choice(cards)
cardsLeft = cards.replace(card, '', 1)
How to remove one character from a string:
Here is an example where there is a stack of cards represented as characters in a string.
One of them is drawn (import random module for the random.choice() function, that picks a random character in the string).
A new string, cardsLeft, is created to hold the remaining cards given by the string function replace() where the last parameter indicates that only one "card" is to be replaced by the empty string...
On Python 2, you can use UserString.MutableString to do it in a mutable way:
>>> import UserString
>>> s = UserString.MutableString("EXAMPLE")
>>> type(s)
<class 'UserString.MutableString'>
>>> del s[3] # Delete 'M'
>>> s = str(s) # Turn it into an immutable value
>>> s
'EXAPLE'
MutableString was removed in Python 3.
Another way is with a function,
Below is a way to remove all vowels from a string, just by calling the function
def disemvowel(s):
return s.translate(None, "aeiouAEIOU")
Here's what I did to slice out the "M":
s = 'EXAMPLE'
s1 = s[:s.index('M')] + s[s.index('M')+1:]
To delete a char or a sub-string once (only the first occurrence):
main_string = main_string.replace(sub_str, replace_with, 1)
NOTE: Here 1 can be replaced with any int for the number of occurrence you want to replace.
You can simply use list comprehension.
Assume that you have the string: my name is and you want to remove character m. use the following code:
"".join([x for x in "my name is" if x is not 'm'])
If you want to delete/ignore characters in a string, and, for instance, you have this string,
"[11:L:0]"
from a web API response or something like that, like a CSV file, let's say you are using requests
import requests
udid = 123456
url = 'http://webservices.yourserver.com/action/id-' + udid
s = requests.Session()
s.verify = False
resp = s.get(url, stream=True)
content = resp.content
loop and get rid of unwanted chars:
for line in resp.iter_lines():
line = line.replace("[", "")
line = line.replace("]", "")
line = line.replace('"', "")
Optional split, and you will be able to read values individually:
listofvalues = line.split(':')
Now accessing each value is easier:
print listofvalues[0]
print listofvalues[1]
print listofvalues[2]
This will print
11
L
0
Two new string removal methods are introduced in Python 3.9+
#str.removeprefix("prefix_to_be_removed")
#str.removesuffix("suffix_to_be_removed")
s='EXAMPLE'
In this case position of 'M' is 3
s = s[:3] + s[3:].removeprefix('M')
OR
s = s[:4].removesuffix('M') + s[4:]
#output'EXAPLE'
from random import randint
def shuffle_word(word):
newWord=""
for i in range(0,len(word)):
pos=randint(0,len(word)-1)
newWord += word[pos]
word = word[:pos]+word[pos+1:]
return newWord
word = "Sarajevo"
print(shuffle_word(word))
Strings are immutable in Python so both your options mean the same thing basically.
Is there a way to manipulate a string in Python using the following ways?
For any string that is stored in dot notation, for example:
s = "classes.students.grades"
Is there a way to change the string to the following:
"classes.students"
Basically, remove everything up to and including the last period. So "restaurants.spanish.food.salty" would become "restaurants.spanish.food".
Additionally, is there any way to identify what comes after the last period? The reason I want to do this is I want to use isDigit().
So, if it was classes.students.grades.0 could I grab the 0 somehow, so I could use an if statement with isdigit, and say if the part of the string after the last period (so 0 in this case) is a digit, remove it, otherwise, leave it.
you can use split and join together:
s = "classes.students.grades"
print '.'.join(s.split('.')[:-1])
You are splitting the string on . - it'll give you a list of strings, after that you are joining the list elements back to string separating them by .
[:-1] will pick all the elements from the list but the last one
To check what comes after the last .:
s.split('.')[-1]
Another way is to use rsplit. It works the same way as split but if you provide maxsplit parameter it'll split the string starting from the end:
rest, last = s.rsplit('.', 1)
'classes.students'
'grades'
You can also use re.sub to substitute the part after the last . with an empty string:
re.sub('\.[^.]+$', '', s)
And the last part of your question to wrap words in [] i would recommend to use format and list comprehension:
''.join("[{}]".format(e) for e in s.split('.'))
It'll give you the desired output:
[classes][students][grades]
The best way to do this is using the rsplit method and pass in the maxsplit argument.
>>> s = "classes.students.grades"
>>> before, after = s.rsplit('.', maxsplit=1) # rsplit('.', 1) in Python 2.x onwards
>>> before
'classes.students'
>>> after
'grades'
You can also use the rfind() method with normal slice operation.
To get everything before last .:
>>> s = "classes.students.grades"
>>> last_index = s.rfind('.')
>>> s[:last_index]
'classes.students'
Then everything after last .
>>> s[last_index + 1:]
'grades'
if '.' in s, s.rpartition('.') finds last dot in s,
and returns (before_last_dot, dot, after_last_dot):
s = "classes.students.grades"
s.rpartition('.')[0]
If your goal is to get rid of a final component that's just a single digit, start and end with re.sub():
s = re.sub(r"\.\d$", "", s)
This will do the job, and leave other strings alone. No need to mess with anything else.
If you do want to know about the general case (separate out the last component, no matter what it is), then use rsplit to split your string once:
>>> "hel.lo.there".rsplit(".", 1)
['hel.lo', 'there']
If there's no dot in the string you'll just get one element in your array, the entire string.
You can do it very simply with rsplit (str.rsplit([sep[, maxsplit]]) , which will return a list by breaking each element along the given separator.
You can also specify how many splits should be performed:
>>> s = "res.spa.f.sal.786423"
>>> s.rsplit('.',1)
['res.spa.f.sal', '786423']
So the final function that you describe is:
def dimimak_cool_function(s):
if '.' not in s: return s
start, end = s.rsplit('.', 1)
return start if end.isdigit() else s
>>> dimimak_cool_function("res.spa.f.sal.786423")
'res.spa.f.sal'
>>> dimimak_cool_function("res.spa.f.sal")
'res.spa.f.sal'
I have a list containing the lines of a file.
list1[0]="this is the first line"
list2[1]="this is the second line"
I also have a string.
example="TTTTTTTaaaaaaaaaabcccddeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeefffff"
I want to replace list[0] with the string (example). However I want to keep the word length. For example the new list1[0] should be "TTTT TT TTa aaaaa aaaa". The only solution I could come up with was to turn the string example into a list and use a for loop to read letter by letter from the string list into the original list.
for line in open(input, 'r'):
list1[i] = listString[i]
i=i+1
However this does not work from what I understand because Python strings are immutable? What's a good way for a beginner to approach this problem?
I'd probably do something like:
orig = "this is the first line"
repl = "TTTTTTTaaaaaaaaaabcccddeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeefffff"
def replace(orig, repl):
r = iter(repl)
result = ''.join([' ' if ch.isspace() else next(r) for ch in orig])
return result
If repl could be shorter than orig, consider r = itertools.cycle(repl)
This works by creating an iterator out of the replacement string, then iterating over the original string, keeping the spaces, but using the next character from the replacement string instead of any non-space characters.
The other approach you could take would be to note the indexes of the spaces in one pass through orig, then insert them at those indexes in a pass of repl and return a slice of the result
def replace(orig, repl):
spaces = [idx for idx,ch in enumerate(orig) if ch.isspace()]
repl = list(repl)
for idx in spaces:
repl.insert(idx, " ")
# add a space before that index
return ''.join(repl[:len(orig)])
However I couldn't imagine the second approach to be any faster, is certain to be less memory-efficient, and I don't find it easier to read (in fact I find it HARDER to read!) It also don't have a simple workaround if repl is shorter than orig (I guess you could do repl *= 2 but that's uglier than sin and still doesn't guarantee it'll work)
I want to simplify replacing specific characters of a string in-situ - with a list comprehension. Attempts so far simply return a list of strings - each list item with each character replaced from the check string.
Advice / solutions?
Inputs:
reveal = "password"
ltrTried = "sr"
Required Output:
return = "**ss**r*"
Getting:
('**ss****', '******r*')
If you want to do this using a list comprehension, you'd want to replace it letter by letter like this:
reveal = "".join((letter if letter in ltrFound else "*") for letter in reveal)
Notice that
We're iterating over your reveal string, not your ltrFound list (or string).
Each item is replaced using the ternary operator letter if letter in ltrFound else "*". This ensures that if the letter in reveal is not in ltrFound, it will get replaced with a *.
We end by joining together all the letters.
Just for fun, here's a different way to do this immutably, by using a translation map.
If you wanted to replace everything that was in ltrFound, that would be easy:
tr = str.maketrans(ltrFound, '*' * len(ltrFound))
print(reveal.translate(tr))
But you want to do the opposite, replace everything that's not in ltrFound. And you don't want to build a translation table of all of the 100K+ characters that aren't s. So, what can you do?
You can build a table of the 6 characters that aren't in s but are in reveal:
notFound = ''.join(set(reveal) - set(ltrFound)) # 'adoprw'
tr = str.maketrans(notFound, '*' * len(notFound))
print(reveal.translate(tr))
The above is using Python 3.x; for 2.x, maketrans is a function in the string module rather than a classmethod of the str class (and there are a few other differences, but they don't matter here). So:
import string
notFound = ''.join(set(reveal) - set(ltrFound)) # 'adoprw'
tr = string.maketrans(notFound, '*' * len(notFound))
print(reveal.translate(tr))
try this
re.sub("[^%s]"%guesses,"*",solution_string)
assuming guesses is a string
There is a string, for example. EXAMPLE.
How can I remove the middle character, i.e., M from it? I don't need the code. I want to know:
Do strings in Python end in any special character?
Which is a better way - shifting everything right to left starting from the middle character OR creation of a new string and not copying the middle character?
In Python, strings are immutable, so you have to create a new string. You have a few options of how to create the new string. If you want to remove the 'M' wherever it appears:
newstr = oldstr.replace("M", "")
If you want to remove the central character:
midlen = len(oldstr) // 2
newstr = oldstr[:midlen] + oldstr[midlen+1:]
You asked if strings end with a special character. No, you are thinking like a C programmer. In Python, strings are stored with their length, so any byte value, including \0, can appear in a string.
To replace a specific position:
s = s[:pos] + s[(pos+1):]
To replace a specific character:
s = s.replace('M','')
This is probably the best way:
original = "EXAMPLE"
removed = original.replace("M", "")
Don't worry about shifting characters and such. Most Python code takes place on a much higher level of abstraction.
Strings are immutable. But you can convert them to a list, which is mutable, and then convert the list back to a string after you've changed it.
s = "this is a string"
l = list(s) # convert to list
l[1] = "" # "delete" letter h (the item actually still exists but is empty)
l[1:2] = [] # really delete letter h (the item is actually removed from the list)
del(l[1]) # another way to delete it
p = l.index("a") # find position of the letter "a"
del(l[p]) # delete it
s = "".join(l) # convert back to string
You can also create a new string, as others have shown, by taking everything except the character you want from the existing string.
How can I remove the middle character, i.e., M from it?
You can't, because strings in Python are immutable.
Do strings in Python end in any special character?
No. They are similar to lists of characters; the length of the list defines the length of the string, and no character acts as a terminator.
Which is a better way - shifting everything right to left starting from the middle character OR creation of a new string and not copying the middle character?
You cannot modify the existing string, so you must create a new one containing everything except the middle character.
Use the translate() method:
>>> s = 'EXAMPLE'
>>> s.translate(None, 'M')
'EXAPLE'
def kill_char(string, n): # n = position of which character you want to remove
begin = string[:n] # from beginning to n (n not included)
end = string[n+1:] # n+1 through end of string
return begin + end
print kill_char("EXAMPLE", 3) # "M" removed
I have seen this somewhere here.
card = random.choice(cards)
cardsLeft = cards.replace(card, '', 1)
How to remove one character from a string:
Here is an example where there is a stack of cards represented as characters in a string.
One of them is drawn (import random module for the random.choice() function, that picks a random character in the string).
A new string, cardsLeft, is created to hold the remaining cards given by the string function replace() where the last parameter indicates that only one "card" is to be replaced by the empty string...
On Python 2, you can use UserString.MutableString to do it in a mutable way:
>>> import UserString
>>> s = UserString.MutableString("EXAMPLE")
>>> type(s)
<class 'UserString.MutableString'>
>>> del s[3] # Delete 'M'
>>> s = str(s) # Turn it into an immutable value
>>> s
'EXAPLE'
MutableString was removed in Python 3.
Another way is with a function,
Below is a way to remove all vowels from a string, just by calling the function
def disemvowel(s):
return s.translate(None, "aeiouAEIOU")
Here's what I did to slice out the "M":
s = 'EXAMPLE'
s1 = s[:s.index('M')] + s[s.index('M')+1:]
To delete a char or a sub-string once (only the first occurrence):
main_string = main_string.replace(sub_str, replace_with, 1)
NOTE: Here 1 can be replaced with any int for the number of occurrence you want to replace.
You can simply use list comprehension.
Assume that you have the string: my name is and you want to remove character m. use the following code:
"".join([x for x in "my name is" if x is not 'm'])
If you want to delete/ignore characters in a string, and, for instance, you have this string,
"[11:L:0]"
from a web API response or something like that, like a CSV file, let's say you are using requests
import requests
udid = 123456
url = 'http://webservices.yourserver.com/action/id-' + udid
s = requests.Session()
s.verify = False
resp = s.get(url, stream=True)
content = resp.content
loop and get rid of unwanted chars:
for line in resp.iter_lines():
line = line.replace("[", "")
line = line.replace("]", "")
line = line.replace('"', "")
Optional split, and you will be able to read values individually:
listofvalues = line.split(':')
Now accessing each value is easier:
print listofvalues[0]
print listofvalues[1]
print listofvalues[2]
This will print
11
L
0
Two new string removal methods are introduced in Python 3.9+
#str.removeprefix("prefix_to_be_removed")
#str.removesuffix("suffix_to_be_removed")
s='EXAMPLE'
In this case position of 'M' is 3
s = s[:3] + s[3:].removeprefix('M')
OR
s = s[:4].removesuffix('M') + s[4:]
#output'EXAPLE'
from random import randint
def shuffle_word(word):
newWord=""
for i in range(0,len(word)):
pos=randint(0,len(word)-1)
newWord += word[pos]
word = word[:pos]+word[pos+1:]
return newWord
word = "Sarajevo"
print(shuffle_word(word))
Strings are immutable in Python so both your options mean the same thing basically.