There is some issue with my python code. I am making a program that finds the occurrences of the letter A in a word and if that letter is found and the next letter is not the letter A the A is swapped with the next letter.
As an example TAN being TNA but WHOA staying as WHOA
AARDVARK being ARADVRAK
The issue is when I input ABRACADABRA I get a string index out of range exception. Before I had that exception I had the word that prints it as BRACADABRIi'm not sure why if I have to add another loop in my program.
If you guys also have anymore efficient way to run the code then the way I have please let me know!
def scrambleWord(userInput):
count = 0
scramble = ''
while count < len(userInput):
if userInput[count] =='A' and userInput[count+1] != 'A':
scramble+= userInput[count+1] + userInput[count]
count+=2
elif userInput[count] != 'A':
scramble += userInput[count]
count+=1
if count < len(userInput):
scramble += userInput(len(userInput)-1)
return scramble
#if a is found switch the next letter index with a's index
def main():
userInput = input("Enter a word: ")
finish = scrambleWord(userInput.upper())
print(finish)
main()
When you get to the end of the string and it is an 'A' your program is then asking for the next character which is off the end of the string.
Change the loop so it doesn't include the last character:
while count < len(userInput)-1:
if ...
You can modify your code as below:
def scrambleWord(userInput):
count = 0
scramble = ''
while count < len(userInput):
if count < len(userInput)-1 and userInput[count] =='A' and userInput[count+1] != 'A':
scramble+= userInput[count+1] + userInput[count]
count+=2
else:
scramble += userInput[count]
count+=1
return scramble
You are not checking the condition (count < len(userInput)-1) when logic tries to check for A's occurrence and swap with next letter. It throws string index out of range exception.
The issue arises in your code when last character in input is 'A'.
This is because your first if in the loop tries to access 'count + 1' character during last iteration.
And since there's no character at that position, you get index error.
The simplest solution would be to make a separate if condition for the same.
Updated snippet for while loop might look like this -
# while start
while count < len_: # len_ is length of input
if count + 1 >= len_:
break # break outta loop, copy last character
current = inp[count]
next_ = inp[count + 1]
if current == 'A':
op += ( next_ + current) # op is result
count += 1
else:
op += current
# increment counter by 1
count += 1
# rest of the code after while is same
Another small issue in your code is while copying last character ( after loop ends ), you should use [ ] instead of ( ) to refer last character in input string.
Just for fun :
from functools import reduce
def main():
word = input("Enter a word: ").lower()
scramble = reduce((lambda x,y : x[:-1]+y+'A' \
if (x[-1]=='a' and y!=x[-1]) \
else x+y),word)
print(scramble.upper())
main()
Related
I am trying to find the no. of occurrence of a substring in a string. I know that count function can be used but it is for non-overlapping occurrences.
Here is my code I found online
string = input("Enter the string: ");
sub_string = input("Enter the substring: ")
count = 0
for i in range(0, len(string)):
for j in range(0, len(sub_string)):
if string[i] == sub_string[j]:
j += 1
else:
j = 0
if j == len(sub_string):
count += 1
print(count)
In this, in the 2nd loop we compare each element of sub_string[j] to string[i] which is same in that loop, then how j will increase & increase the count after checking in next if condition.
So the code you have is wrong, since it would pass the if check as long as the last character matches the matches the string, e.g. string
"sagar is sagar not sa saga sagar r" and substring "sagar" would return 4 rather than 3.
Since you use j both to count the number of matches as well as the index for the substring, it gets overwritten in the inner loop each iteration. This means that it would only need to match the very last letter to pass the check below the loop.
You might want to change it to something that checks each character starting at some position and denies it if it doesn't match, e.g.
string = input("Enter the string: ");
sub_string = input("Enter the substring: ")
count = 0
for i in range(0, len(string) - len(sub_string)):
found = True
for j in range(len(sub_string)):
if string[i + j] != sub_string[j]:
found = False
break
if found:
count += 1
In your case only the last elements are equal then the count will increment by one.
for ex:
if string is seg, and sub string is sag the the count will be one.
this happens because in the second loop when j = len(substring)-1, g from seg and sag will be detected as equal. so then count get increment by one.
string = input("Enter the string: ");
sub_string = input("Enter the substring: ")
count = 0
for i in range(0, len(string)):
j=0
while i+j< len(string) and j <len(sub_string):
if string[i+j] == sub_string[j]:
j += 1
else:
break
else:
count += 1
print(count)
try this code, in there if while loop didn't get break count increment by one.
i am new to python and facing a problem i want to skip small "m" with Continue Statement and want to
print other characters but why this is skipping all other characters "eIsXyz" but i want this output
"MyNaeIsXyz" where is the problem
name = "MyNameIsXyz"
len = len(name)-1
start = 0
while(start<=len):
if(name[start]=="m"):
continue
print(name[start])
start += 1
output
M
y
N
a
Here's a much more simpler way
name = 'MyNameIsXyz'
for letter in name:
if letter != 'm':
print(letter)
If you want to do it whit a while loop (using your style)
name = "MyNameIsXyz"
start = 0
while(start<=len(name) - 1):
if name[start] != 'm':
print(name[start])
start += 1
You increment start after continue so you get an infinite loop as soon as you hit name[start]=="m"
name = "MyNameIsXyz"
len = len(name)-1
start = 0
while(start<=len):
if(name[start]=="m"):
start += 1
continue
print(name[start])
start += 1
Will fix your problem most directly, but there are ways to achieve this without continue which are much clearer:
name = "MyNameIsXyz"
for c in name:
if c!='m':
print(c)
or just
name = "MyNameIsXyz".replace("m","")
print(name)
You can try this:
name = "MyNameIsXyz"
result = ""
for i in name:
if i != "m":
result += i
print(result)
continue keyword skip the lower part of this loop. As your increment is in the lower part so it's not gonna increase the value of start. The value of start is getting the same value again and again and make an infinite loop.
Either you've to increment the value before continue or you can do it in a simple way like this..
name = "MyNameIsXyz"
for letter in name:
if letter != 'm':
print(letter, end="")
I'm pretty new to python and I'm having trouble with my
if then else statements and I only get is "no repeating vowels" which mean my rep_vowel is still returning 0
so the program rules are as follows.
if no vowel appears next to itself (e.g. hello), then print:
no vowel repeats
if exactly one vowel is repeated in sequence at least once (e.g. committee) then print a message that indicates which vowel repeats:
only vowel e repeats
if more than one vowel repeats (e.g. green door) then print:
more than one vowel repeats
ignore upper case - lower case differences: assume all the input is always lowercase
answer = input("Enter a string: ")
rep_vowel = 0
i = 0
length_Answer = len(answer)
next_string = 1
curChar = answer[0+rep_vowel]
for i in range(0,length_Answer):
if answer[0 + i] in ["a","e","i","o","u"]:
i =+ 1
next_string = answer[0+i+i]
if next_string == answer:
rep_vowel =+ 1
if rep_vowel == 0:
print("no repeating vowles")
elif rep_vowel > 1:
print("more than 1 repeating vowels")
else:
print ("the letter "+ str(curChar) +" repeats")
You have a few mistakes so i'll try to address several of them:
You do a lot of [0 + something] indexing, which is useless, since 0 + something always equals to something, so yo should just do indexing with [something]
Changing the value of i with i += 1 is bad because you are already increasing it as part of the loop
All you have to do to find a match is simply match the current letter to the next one, if both are the same and they are also vowels, you've found a match.
You are initializing unnecessary variables such as i = 0 only to have them overridden in the next lines
Adding all of those together:
answer = input("Enter a string: ")
vowels = "aeiou"
repeats = [] # this list will hold all repeats of vowels
for i in range(len(answer) - 1): # i'll explain the -1 part at the end
if answer[i] in vowels and answer[i] == answer[i + 1]:
repeats.append(answer[i])
if len(repeats) == 0:
print("no repeating vowles")
elif len(repeats) > 1:
print("more than 1 repeating vowels")
else:
print("the letter " + repeats[0] + " repeats")
This still doesn't take every possible input into account, but it should get you started on a final solution (or perhaps that's enough). For example, input of teest will give the correct result but the input of teeest doesn't (depends on your definition of correct).
About the len(answer-1) range, that's only to make sure we don't go out of bounds when doing answer[i + 1], so we're stopping on the next to last letter instead.
Firstly, you have to indent your code.
to say if (condition) then do print('hello') you write it this way:
if condition:
print('hello')
Secondly, you are using i =+ 1 which is the same as i=1
I think you meant i +=1 which is i = i+1
Finally, I suggest this code:
answer = input("Enter a string: ")
vowel_repeated_count = 0
length_Answer = len(answer)
i=0
while (i <length_Answer-1):
#we check if it's a vowel
if answer[i] in ["a","e","i","o","u"]:
#we check if it's followed by the same vowel
if answer[i+1] == answer[i]:
#increment the vowel_repeated_count
vowel_repeated_count +=1
#we save the vowel for the display
vowel = answer[i]
#we skip the other same repeated vowels
#example: abceeed, we skip the third e
while (answer[i] == vowel and i < length_Answer-1):
i +=1
#we add this incrementation because we're in a while loop
i +=1
if vowel_repeated_count == 0:
print("no repeating vowles")
elif vowel_repeated_count == 1:
print("the letter "+ str(vowel) +" repeats")
else:
print ("more than 1 repeating vowels")
You have some logical errors. It's time consuming to edit that. You can try this, I have modified your code. Hope it will work for you. I have commented beside every important line.
answer = input("Enter a string: ")
is_found = {} #a dictionary that will hold information about how many times a vowel found,initially all are 0
is_found["a"]=0
is_found["e"] = 0
is_found['i']=0
is_found['o']=0
is_found['u']=0
vowels =["a","e","i","o","u"]
for i in range(0,len(answer)):
if answer[i] in vowels:
is_found[answer[i]] = is_found[answer[i]]+1 # if a vowel found then increase its counter
repeated=0 #let 0 repeated vowel
previously_repeated=False #to trace whether there is a previously repeated character found
curChar=None
for key,value in is_found.items(): #iterate over dictionary
if previously_repeated and value>1: #if a vowel found and previously we have another repeated vowel.
repeated=2
elif previously_repeated==False and value>1: # we don't have previously repeated vowel but current vowel is repeated
curChar=key
previously_repeated=True
repeated=1
if repeated== 0:
print("no repeating vowles")
elif repeated> 1:
print("more than 1 repeating vowels")
else:
print ("the letter "+ str(curChar) +" repeats")
There is no need to increment your counter i. In your for loop, it will increment itself each time it goes through the for loop. Also, you need a variable to keep track of how many times the vowel repeats.
answer = input("Enter a string: ")
rep_vowel = 0
length_Answer = len(answer)
vowelList=["a","e","i","o","u"]
vowelRepeated = []
#this will go from i=0 to length_Answer-1
for i in range(length_Answer):
if (answer[i] in vowelList) and (answer[i+1] in vowelList):
if (answer[i] == answer[i+1]):
vowelRepeated.append(answer[i])
repVowel += 1
if rep_vowel==0:
print("no repeating vowels")
elif rep_vowel==1:
print("only one vowel repeated:")
print(vowelRepeated)
else:
print("multiple vowels repeated:")
print(vowelRepeated)
for such counting, I will prefer to use a dictionary to keep the counting number. Your code has been modified for your reference
answer = input("Enter a string: ")
length_Answer = len(answer)
count = dict()
for i in range(length_Answer):
if answer[i] in ["a","e","i","o","u"]:
if answer[i+1] == answer[i]:
if answer[i] in count:
count[answer[i]] += 1
else:
count[answer[i]] = 1
rep_vowel = len(count)
if rep_vowel == 0:
print("no repeating vowles")
elif rep_vowel > 1:
print("more than 1 repeating vowels")
else:
for k in count:
vowel = k
print("the letter " + vowel + " repeats")
You have a few issues with your solution :
1) You never use curChar, i'm guessing you wanted to enter the next_string value into it after the '==' statement.
2) You compare your next_string to answer, this will always be a false statement.
3) Also no need to use [0+i], [i] is good enough
Basically what you want to do is this flow :
1) Read current char
2) Compare to next char
3) If equal put into a different variable
4) If happens again raise a flag
Optional solution :
vowel_list = ["a","e","i","o","u"]
recuring_vowel_boolean_list = [answer[index]==answer[index+1] and answer[index] in vowel_list for index in range(len(answer)-1)]
if not any(recuring_vowel_boolean_list ):
print("no repeating vowels")
elif (recuring_vowel_boolean_list.count(True) > 1):
print("More then 1 repeating vowels")
else:
print("The letter {} repeats".format(answer[recuring_vowel_boolean_list.index(True)]))
I am trying to count the longest length of string in alphabetical order
s = 'abcv'
longest = 1
current = 1
for i in range (len(s) - 1):
if s[i] <= s[i+1]:
current += 1
else:
if current > longest:
longest = current
current = 0
i += 1
print longest
For this specific string, 'Current' ends up at the correct length, 4, but never modifies longest.
EDIT: The following code now runs into an error
s = 'abcv'
current = 1
biggest = 0
for i in range(len(s) - 1):
while s[i] <= s[i+1]:
current += 1
i += 1
if current > biggest:
biggest = current
current = 0
print biggest
It seems my logic is correct , but I run into errors for certain strings. :(
Although code sources are available on the internet which print the longest string, I can't seem to find how to print the longest length.
break will jump behind the loop (to sam indentation as the for statement. continue will jump to start of loop and do the next iteration
Your logic in the else: statement does not work - you need to indent it one less.
if s[i] <= s[i+1]:
checks for "is actual char less or equal then next char" - if this is the case you need to increment your internal counter and set longest if it is longer
You might get into trouble with if s[i] <= s[i+1]: - you are doing it till len(s)-1. "jfjfjf" is len("jfjfjf") = 6 - you would iterate from 0 to 5 - but the if accesses s[5] and s[6] which is more then there are items.
A different approach without going over explicit indexes and split into two responsibilities (get list of alphabetical substring, order them longest first):
# split string into list of substrings that internally are alphabetically ordered (<=)
def getAlphabeticalSplits(s):
result = []
temp = ""
for c in s: # just use all characters in s
# if temp is empty or the last char in it is less/euqal to current char
if temp == "" or temp[-1] <= c:
temp += c # append it to the temp substring
else:
result.append(temp) # else add it to the list of substrings
temp = "" # and clear tem
# done with all chars, return list of substrings
return result
# return the splitted list as copy after sorting reverse by length
def SortAlphSplits(sp, rev = True):
return sorted(sp, key=lambda x: len(x), reverse=rev)
splitter = getAlphabeticalSplits("akdsfabcdemfjklmnopqrjdhsgt")
print(splitter)
sortedSplitter = SortAlphSplits(splitter)
print (sortedSplitter)
print(len(sortedSplitter[0]))
Output:
['ak', 's', 'abcdem', 'jklmnopqr', 'dhs']
['jklmnopqr', 'abcdem', 'dhs', 'ak', 's']
9
This one returns the array of splits + sorts them by length descending. In a critical environment this costs more memory then yours as you only cache some numbers whereas the other approach fills lists and copies it into a sorted one.
To solve your codes index problem change your logic slightly:
Start at the second character and test if the one before is less that this. That way you will ever check this char with the one before
s = 'abcvabcdefga'
current = 0
biggest = 0
for i in range(1,len(s)): # compares the index[1] with [0] , 2 with 1 etc
if s[i] >= s[i-1]: # this char is bigger/equal last char
current += 1
biggest = max(current,biggest)
else:
current = 1
print biggest
You have to edit out the else statement. Because consider the case where the current just exceeds longest, i.e, from current = 3 and longest =3 , current becomes 4 by incrementing itself. Now here , you still want it to go inside the if current > longest statement
s = 'abcv'
longest = 1
current = 1
for i in range (len(s) - 1):
if s[i] <= s[i+1]:
current += 1
#else:
if current > longest:
longest = current
current = 0
i += 1
longest = current
print longest
Use a while condition loop, then you can easy define, at what condition your loop is done.
If you want QualityCode for longterm:
While loop is better practice than a break, because you see the Looping condition at one place. The simple break is often worse to recognize inbetween the loopbody.
At the end of the loop, current is the length of the last substring in ascending order. Assigning it to longest is not right as the last substring in ascending is not necessarily the longest.
So longest=max(current,longest) instead of longest=current after the loop, should solve it for you.
Edit: ^ was for before the edit. You just need to add longest=max(current,longest) after the for loop, for the same reason (the last ascending substring is not considered). Something like this:
s = 'abcv'
longest = 1
current = 1
for i in range (len(s) - 1):
if s[i] <= s[i+1]:
current += 1
else:
if current > longest:
longest = current
current = 0
i += 1
longest=max(current,longest) #extra
print longest
The loop ends when there is no code after the tab space so technically your loop has already ended
I'm using Python (3.x) to create a simple program for an assignment. It takes a multiline input, and if there is more than one consecutive whitespace it strips them out and replaces it with one whitespace. [That's the easy part.] It must also print the value of the most consecutive whitespaces in the entire input.
Example:
input = ("This is the input.")
Should print:
This is the input.
3
My code is below:
def blanks():
#this function works wonderfully!
all_line_max= []
while True:
try:
strline= input()
if len(strline)>0:
z= (maxspaces(strline))
all_line_max.append(z)
y= ' '.join(strline.split())
print(y)
print(z)
if strline =='END':
break
except:
break
print(all_line_max)
def maxspaces(x):
y= list(x)
count = 0
#this is the number of consecutive spaces we've found so far
counts=[]
for character in y:
count_max= 0
if character == ' ':
count= count + 1
if count > count_max:
count_max = count
counts.append(count_max)
else:
count = 0
return(max(counts))
blanks()
I understand that this is probably horribly inefficient, but it seems to almost work. My issue is this: I would like to, once the loop is finished appending to all_lines_max, print the largest value of that list. However, there doesn't seem to be a way to print the max of that list without doing it on every line, if that makes sense. Any ideas on my convoluted code?
Just print the max of all_line_max, right where you currently print the whole list:
print(max(all_line_max))
but leave it at the top level (so dedent once):
def blanks():
all_line_max = []
while True:
try:
strline = input()
if strline:
z = maxspaces(strline)
all_line_max.append(z)
y = ' '.join(strline.split())
print(y)
if strline == 'END':
break
except Exception:
break
print(max(all_line_max))
and remove the print(z) call, which prints the maximum whitespace count per line.
Your maxspaces() function adds count_max to your counts list each time a space is found; not the most efficient method. You don't even need to keep a list there; count_max needs to be moved out of the loop and will then correctly reflect the maximum space count. You also don't have to turn the sentence into a list, you can directly loop over a string:
def maxspaces(x):
max_count = count = 0
for character in x:
if character == ' ':
count += 1
if count > max_count:
max_count = count
else:
count = 0
return max_count