import re
for test in range(int(input())):
a = input() # input a string
n = a.replace("=", "") # if string contains '='then remove it
gg = re.findall(r ">+", n) # count >
l1 = len(max(gg, key = len)) # count consecutive >
hh = re.findall(r "<+", n) # count <
l2 = len(max(hh, key = len)) # count consecutive <
print(max(l1, l2) + 1) # print max of two + 1
Input is :
4
<<<
<><
<=>
<=<
I am encountering a error if I run the above code.I read it on SO only the syntax still I am getting error:
Traceback (most recent call last):<br/> File "/home/fea0d5e04ac92cb3a1e4f041940f2dfc.py", line 8, in <module><br/>
l2=len(max(hh, key=len))<br/> ValueError: max() arg is an empty sequence
max fails on an empty sequence.
Python >= 3.4
max takes an optional default argument:
l1 = len(max(gg, key = len, default=0)) # count consecutive >
Python < 3.4
Add a guard to check if the list is empty
if len(hh) > 0:
l2 = len(max(hh, key = len)) # count consecutive <
else:
l2 = 0
Related
Here is what I have tried
c = ['8781' ,'2740', '1413', '3060', '5074']
d = ['8853' ,'2812', '1355', '2986', '5107']
start = map(int, c)
end = map(int, d)
for n,m in zip(start,end):
if n < m:
preS = map(lambda x:x-21, start)
preE = map(lambda x:x+20, end)
print (preS, preE)
else:
preS = map(lambda x:x-20, end)
preE = map(lambda x:x+20, start)
print (preS, preE)
Here my else part of loop is not executing and I got multiple lines of same output. Whats wrong here?
I am expecting in following way:
preS preE
8760 8873
2719 2832
1433 1335
3080 2966
5053 5127
I get the following output:
([8760, 2719, 1392, 3039, 5053], [8873, 2832, 1375, 3006, 5127])
([8739, 2698, 1371, 3018, 5032], [8893, 2852, 1395, 3026, 5147])
([8719, 2678, 1351, 2998, 5012], [8913, 2872, 1415, 3046, 5167])
([8719, 2678, 1351, 2998, 5012], [8913, 2872, 1415, 3046, 5167])
([8718, 2677, 1350, 2997, 5011], [8913, 2872, 1415, 3046, 5167])
I would really appreciate for answers.
You are updating and printing the whole result lists in each iteration. The result from the last iteration "wins", and all elements in the result from the earlier iterations are overwritten.
Instead, you need to handle the elements individually, and only print the result once at the end:
preS = []
preE = []
for n, m in zip(start, end):
if n < m:
preS.append(n - 21)
preE.append(m + 20)
else:
preS.append(n - 20)
preE.append(m + 20)
print preS, preE
The whole thing can be expressed more concisely by a list comprehension:
preS, preE = zip(*[(n - 21, m + 20) if n < m else (n - 20, m + 20)
for n, m in zip(start, end)])
It uses the zip(*list) idiom to transpose the list of pairs.
I am attempting to analyze data sets as lists of differing lengths. I am calling lines (rows) of my data set one by one to be analyzed by my function. I want the function to still be run properly regardless of the length of the list.
My Code:
f = open('DataSet.txt')
for line in iter(f):
remove_blanks = ['']
entries = line.split()
''.join([i for i in entries if i not in remove_blanks])
trash = (entries[0], entries[1])
time = int(entries[2])
column = [int(v) for v in entries[3:]]
def myFun():
print(entries)
print_string = ''
if column[0] == 100:
if column[1] >= 250 and column[2] == 300:
if len(column) >= 9:
digit = [chr(x) for x in column[4:9]]
print_string = ('code: ' + ''.join(str(digit[l]) for l in range(5)) + ' ')
if len(column) >= 13:
optional_digit = [chr(d) for d in column[9:13]]
for m in range(0, 4):
print_string += 'Optional Field: ' + optional_digit[m] + ''
else:
print_string += 'No Optional Field '
pass
pass
print(print_string)
print('')
myFun()
f.close()
What is happening is if the length of a line of my data is not long enough (i.e. the list ends at column[6]), I get the error:
line 17, in function
print('Code: ' + digit[l])
IndexError: list index out of range
I want it to still print Code: #number #number #number #number and leave any non-existent columns as blanks when it is printed so that one line may print as Code: ABC9 and the next print as Code: AB if there are differing list lengths.
Please help! :)
Well, just make sure you're not looping over a list longer than available:
print_string = 'code: ' + ''.join(str(digit[l]) for l in range(min(5, len(digit)))) + ' '
or better:
print_string = "code {} ".format("".join(str(dig) for dig in digit[:5]))
Although I have a feeling you're over-complicating this.
I have an empty list, (r) and declared first element as r[0] = a
import time, urllib.request,random
def getDictionary():
word_site = "http://svnweb.freebsd.org/csrg/share/dict/words?view=co&content-type=text/plain"
response = urllib.request.urlopen(word_site)
txt = response.read()
return txt.splitlines()
def getWordsList(listOfWords, sample):
word = ""
randWords = []
for i in range(0,sample):
while(len(word) <=2):
word = random.choice(listOfWords).decode('utf-8')
randWords.append(word)
word = ""
return randWords
start = True
noOfWords = 25
words = getDictionary()
wordsList = getWordsList(words, noOfWords)
start = True
print ("\nINSTRUCTIONS\nWhen the coundown gets to zero, type the word in lowercase letters!\n That's the only rule!")
name = input("What is your name? ")
name = name.split(" ")
input("Press enter when ready...")
while start == True:
print("Game will start in: ")
print ("3 seconds")
time.sleep(1)
print ("2 seconds")
time.sleep(1)
print ("1 seconds")
time.sleep(1)
times = []
k = list()
r = list()
for i in range(25):
startTime = time.time()
userWord = input(str(i+1) + ". " + wordsList[i].capitalize() + " " )
k.append(wordsList[i].capitalize())
if (userWord.lower() == wordsList[i].lower()):
endTime = time.time()
times.append(endTime - startTime)
r[i] = str(endTime - startTime)
else:
times.append("Wrong Word")
r[i] = ("Wrong Word")
Above is where I am having a problem.
for i in range(25):
startTime = time.time()
print (str(i+1) + ". " + str(k[i]) + ": " + str(times[i]) )
a = 0
for i in range(25):
a = a+i
for i in range(25):
if r[i] == "Wrong Word":
r = r.pop(i)
b = (a/len(r))
c = round(b, 2)
print (c)
start = False
here is my error:
r[i] = "Wrong Word"
IndexError: list assignment index out of range
The pop() method removes an element from the list and returnes it (see an example). What I think is happening is that at some point the condition of the if statment resolves to true. Next, after calling r.pop(i) r is replaced by its i-th element. It's probpably a string so calling its (i+1)-th element later can result in Index out of range error.
In other words, something like this is happening:
r = ["a", "foo", "bar", "baz"]
for i in range(4):
if r[i] == "a": # for i=0 this gives "a" == "a"
r = r.pop(i) # later,this results in r = "a"
next loop iteration with i = 1 will result in "a"[1] which will result in Index out of range.
All in all instead of:
for i in range(25):
if r[i] == "Wrong Word":
r = r.pop(i)
you could just write:
r = [item for item in r if item != "Wrong word"]
which would be also more pythonic solution.
I am trying to implement the merge sort algorithm using the following code but am getting a list index is out of range error.
def mergeSort (unSortedList):
if len(unSortedList) == 1 :
return unSortedList
else:
midpoint = len(unSortedList)//2
A = mergeSort (unSortedList[:midpoint] )
B = mergeSort (unSortedList[midpoint:] )
i = 0
j = 0
C = []
for k in range(len(unSortedList)):
if A[i] >= B[j]:
C.append(A[i])
if i == len(A):
C.append(B[j:])
else:
i += 1
elif A[i] < B[j] :
C.append(B[j])
if j == len(B):
C.append(A[i:])
else:
j += 1
return C
testlist = [2,1,4,2,5,6,8,9]
print (mergeSort(testlist))
Any help would be appreciated.
Here is my version of your mergeSort, with the merge function extracted:
def mergeSort (unSortedList):
if len(unSortedList) == 1 :
return unSortedList
else:
midpoint = len(unSortedList)//2
A = mergeSort (unSortedList[:midpoint] )
B = mergeSort (unSortedList[midpoint:] )
return merge(A, B)
def merge(a, b):
i = 0
j = 0
c = []
while True:
if a[i] < b[j]:
c.append(b[j])
j += 1
elif a[i] >= b[j]:
c.append(a[i])
i += 1
if i == len(a):
c.extend(b[j:])
break
if j == len(b):
c.extend(a[i:])
break
return c
Output:
>>> testlist = [2,1,4,2,5,6,8,9]
>>> mergeSort(testlist)
[9, 8, 6, 5, 4, 2, 2, 1]
Couple of things to note:
Appending a list to a list. When you do C.append(A[j:]) you end up with nested lists. That is because A[j:] always returns a list. You either need to use list addition - C += A[j:] - or call extend - C.extend(A[j:])
Missing breaks. When your i or j got to the end of their lists you correctly appended the rest of the other list but you did not terminate the loop. That is what caused the range error because in the next iteration (which should not happen) you tried to get an item at the index equal to the length of the list which is out of range.
I create a list of dictionaries from excel. The code is listed below. What happens is the list contains the last row excel values for all the rows. I tried in python shell. It works fine. Why all the rows get updated with last row values?
d = {}
l = []
up = os.path.join(request.folder,'uploads')
workbook = xlrd.open_workbook(os.path.join(request.folder,'uploads','meas.xls'))
worksheet = workbook.sheet_by_name('Sheet1')
num_rows = worksheet.nrows - 1
num_cells = worksheet.ncols - 1
curr_row = -1
while curr_row < num_rows:
curr_row += 1
row = worksheet.row(curr_row)
#print 'Row:', curr_row
curr_cell = -1
while curr_cell < num_cells:
curr_cell += 1
# Cell Types: 0=Empty, 1=Text, 2=Number, 3=Date, 4=Boolean, 5=Error, 6=Blank
cell_type = worksheet.cell_type(curr_row, curr_cell)
cell_value = worksheet.cell_value(curr_row, curr_cell)
#print ' ', cell_type, ':', cell_value
if curr_cell == 0:
d['loc_of_work'] = cell_value
if curr_cell == 1:
d['n'] = cell_value
if curr_cell == 2:
d['t'] = cell_value
if curr_cell == 3:
d['l'] = cell_value
if curr_cell == 4:
d['b'] = cell_value
if curr_cell == 5:
d['d'] = cell_value
print 'dict'
print d.items()
l.append(d)
print 'len of list:'
print len(l)
print 'list:'
for i,j in enumerate(l):
print i,j
The issue is you are declaring d outside the while loop, which means within the loop you are simply overwriting the same dict with new values on every iteration. Your list simply contains multiple references to the same dict object, which contains the values from the last row because those are the last values to be written to the dict (all previous values are overwritten)
moveoing:
d = {}
inside the first while loop should fix your issue