I have a binary search that searches a list from a user given input of an email. I get no errors and I get no output from it. I can't see where its going wrong?
def BubbleSort(logindata):
NoSwaps = 1
N = len(logindata)
logindata = list(logindata)
while NoSwaps == 1:
Count = 1
NoSwaps = 0
for Count in range(N-1):
if logindata[Count] > logindata[Count+1]:
temp = logindata[Count]
logindata[Count] = logindata[Count+1]
logindata[Count+1]=temp
NoSwaps=1
return tuple(logindata)
def BinarySearch(logindata,ItemSought):
First=0
Last=len(logindata)-1
ItemFound = False
SearchFailed = False
while ItemFound == False or SearchFailed == False:
Midpoint = (First + Last) // 2
if logindata[Midpoint] == ItemSought:
print("Item Found")
ItemFound = True
print("Item Found")
break
elif logindata[Midpoint][0] > ItemSought:
Last = Midpoint - 1
else:
First = Midpoint + 1
if __name__ == "__main__":
logindata=["tom#gmail.com","Password1"],["harry#gmail.com","Password2"],["jake#gmail.com","Password3"]
logindata=BubbleSort(logindata)
print(logindata)
ItemSought=input("Enter username")
BinarySearch(logindata,ItemSought)
In
if logindata[Midpoint] == ItemSought:
you compare list with a string. So I think you need
if logindata[Midpoint][0] == ItemSought:
You never terminate the search. If the item isn't in the list, you get to a stable midpoint and loop infinitely. If you do find the item, you loop infinitely on that (see Yehven's answer).
I traced it with the additions you see here:
SearchFailed = False
iter = 0
while iter < 10 and (ItemFound == False or SearchFailed == False):
iter += 1
Midpoint = (First + Last) // 2
print (First, Midpoint, Last, ItemSought)
if logindata[Midpoint] == ItemSought:
Note that you don't ever change SearchFailed. For instance, when I search for "harry", the loop hits a stable infinite point at (0, -1, -2) for First, Middle, Last.
Is that enough of a hint to let you fix it yourself?
Related
Hello this is my first question and sorry I don't know how to phrase it,
I am trying to create a two list. The first list is for one set of codes (code1) and is validated in the VC function. The second function (VC) is to validate the second list. Both functions work well in validating the numbers. However in the third function (add_validations). In that function I want to repeat VC and VQ until the user either types in END or either of the functions return False. When true I want the inputs to be appended into the two separate lists. However, the third function not only does not append any of the list it does not identify/run either of the two functions and comes up with:
TypeError: int() argument must be a string, a bytes-like object or a number, not 'NoneType'
And I'm sorry I didn't know which code to add so I added everything (delete if not allowed sorry):
Code:
def add_validations():
code1 = []
code2 = []
VC()
VQ()
while True:
record = []
i = VC()
q = VQ()
if i != "END":
VQ()
VC()
code1.append(int(i))
code2.append(int(q))
elif VC == True and VQ() == True:
VQ()
VC()
code1.append(int(i))
code2.append(int(q))
elif VC == False and VQ() == True:
print("Invalid code")
else:
print("Invalid quantity")
return code1,code2
def VC():
i = input("What is the item code \n")
minimum = 0
maximum = 39
if i == "END":
i = "END"
return showRecord()
elif int(i) > minimum and int(i) <= maximum:
return int(i)
True
else:
False
def VQ():
q = input("What quanity \n")
minimum = 0
maximum = 49
if q == "END":
isValidCode = "END"
return showRecord()
elif int(q) > minimum and int(q) <= maximum:
True
else:
False
I need to check if a string is a valid number or not.
Here are some examples of valid:
1234
-1234
12.4
0.6
-0.6
-1234567890.123456789
Non-valid:
+123
123.
.6
00.6
12-.6335
If the first digit is a 0, a decimal point "." must come after it.
I have tried the following code but it says "time limit exceeded". I'm not sure what that means.
def valid_float(number_string):
counter = 0
if number_string[0].isdigit() or number_string[0] == "-" or number_string[0] == "0":
while number_string[0] == "-":
if number_string[1].isdigit():
counter += 1
else:
counter = 0
while number_string[0].isdigit():
if number_string[1] == "." and number_string[2].isdigit():
counter += 1
else:
counter = 0
while number_string[0] == "0":
if number_string[1] == ".":
counter += 1
else:
counter = 0
if counter == 3:
return True
else:
return False
else:
counter = 0
The error you get means that the program keeps going for a long time because it is 'stuck' somewhere. Most of the time its because of a bad recursion function or, in this case, a while loop that will loop forever.
Your while loops will loop forever because you don't change the thing it checks as condition: if the condition is true in the beginning it will be true all the time so the program will never quit the while loop.
I wanted to correct your code but I can't figure out what you where trying so here is some code that will hopefully help you out:
for i in range(0,len(number_string)):
if i == 0 and number_string[0] == "." :
return false
if i != 0 and number_string[0] == "." :
continue
if i == 0 and number_string[0] == "-" :
continue
if i == 0 and number_string[0] == "0" and len(number_string[0])>1:
if number_string[1] != "." :
return false
if number_string[i].isdigit():
continue
return false
I have this code that should break once it fulfills a certain condition, ie when the isuniquestring(listofchar) function returns True, but sometimes it doesn't do that and it goes into an infinite loop. I tried printing the condition to check if there's something wrong with the condition, but even when the condition is printed true the function still continues running, I have no idea why.
one of the strings that throws up an infinite loop is 'thisisazoothisisapanda', so when I do getunrepeatedlist('thisisazoothisisapanda'), it goes into an infinite loop.
would be really grateful if someone could help
thanks!
Here's my code:
def getunrepeatedlist(listofchar):
for ch in listofchar:
if isrepeatedcharacter(ch,listofchar):
listofindex = checkrepeatedcharacters(ch,listofchar)
listofchar = stripclosertoends(listofindex,listofchar)
print (listofchar)
print (isuniquestring(listofchar))
if isuniquestring(listofchar):
return listofchar
#print (listofchar)
else:
getunrepeatedlist(listofchar)
return listofchar
just for reference, these are the functions I called
def isrepeatedcharacter(ch,list):
if list.count(ch) == 1 or list.count(ch) == 0:
return False
else:
return True
def checkrepeatedcharacters(ch,list):
listofindex=[]
for indexofchar in range(len(list)):
if list[indexofchar] == ch:
listofindex.append(indexofchar)
return listofindex
def stripclosertoends(listofindices,listofchar):
stringlength = len(listofchar)-1
if listofindices[0] > (stringlength-listofindices[-1]):
newstring = listofchar[:listofindices[-1]]
elif listofindices[0] < (stringlength-listofindices[-1]):
newstring = listofchar[listofindices[0]+1:]
elif listofindices[0] == (stringlength-listofindices[-1]):
beginningcount = 0
endcount = 0
for index in range(listofindices[0]):
if isrepeatedcharacter(listofchar[index],listofchar):
beginningcount += 1
for index in range(listofindices[-1]+1,len(listofchar)):
if isrepeatedcharacter(listofchar[index],listofchar):
endcount += 1
if beginningcount < endcount:
newstring = listofchar[:listofindices[-1]]
else:
#print (listofindices[0])
newstring = listofchar[listofindices[0]+1:]
#print (newstring)
return newstring
def isuniquestring(list):
if len(list) == len(set(list)):
return True
else:
return False
It may be due to the fact that you are changing listofchar in your for loop. Try cloning that variable to a new name and use that variable for manipulations and return the new variable.
Hey everyone im new here and im trying to make a game called HiQ now i got the board drawn and everything and i can click on one of the pieces, but when i do the piece does change color and i get an error in the shell as well (listed below) im not sure why im getting this and i was hoping you guys could give me better insight. Ill provide my code below as well and it is coded in python 3, thank you
builtins.IndexError: list index out of range
boardcirc =[[0,0,0,1,1,1,0,0,0],
[0,0,0,1,1,1,0,0,0],
[0,0,0,1,1,1,0,0,0],
[1,1,1,1,1,1,1,1,1],
[1,1,1,1,2,1,1,1,1],
[1,1,1,1,1,1,1,1,1],
[0,0,0,1,1,1,0,0,0],
[0,0,0,1,1,1,0,0,0],
[0,0,0,1,1,1,0,0,0]]
def HiQ():
splash_screen()
make_board()
def make_board():
make_sqr()
make_circ()
get_click()
def get_click():
global count, boardcirc
while 1!=0:
count = count - 1
displaymessage("Pieces: " + str(count))
where = win.getMouse()
col = where.x//90
row = where.y//90
valid_move(row,col)
make_move(row,col)
def valid_move(row,col):
if boardcirc[row][col] == 0:
return False
if boardcirc[row-1][col] == 1 and boardcirc[row-2][col] == 1:
return True
if boardcirc[row+1][col] == 1 and boardcirc[row+2][col] == 1:
return True
if boardcirc[row][col-1] == 1 and boardcirc[row][col-2] == 1:
return True
if boardcirc[row][col+1] == 1 and boardcirc[row][col+2] == 1:
return True
def make_move(row,col):
while valid_move(row,col) == True:
col = (col*85)+42
row = (row*85)+42
circ = Circle(Point(col,row),35)
circ.setFill("white")
circ.draw(win)
thats everything that applies to the error
For your valid_move(row,col), you can't have all those if statements.
Instead of doing this, use elif's after the initial if statement, and don't forget to write an else statement
if boardcirc[row][col] == 0:
return False
if boardcirc[row-1][col] == 1 and boardcirc[row-2][col] == 1:
return True
elif boardcirc[row+1][col] == 1 and boardcirc[row+2][col] == 1:
return True
elif boardcirc[row][col-1] == 1 and boardcirc[row][col-2] == 1:
return True
elif boardcirc[row][col+1] == 1 and boardcirc[row][col+2] == 1:
return True
else:
return False
So i wrote this code and it passes the first test case, and fails all the rest. However, I can't seem to find an input that breaks it. Maybe it's because I've been staring at the code too long, but i would appreciate any help.
The algorithm uses two priority queues for the smallest and largest halves of the current list. Here's the code:
#!/bin/python
import heapq
def fix(minset, maxset):
if len(maxset) > len(minset):
item = heapq.heappop(maxset)
heapq.heappush(minset, -item)
elif len(minset) > (len(maxset) + 1):
item = heapq.heappop(minset)
heapq.heappush(maxset, -item)
N = int(raw_input())
s = []
x = []
for i in range(0, N):
tmp = raw_input()
a, b = [xx for xx in tmp.split(' ')]
s.append(a)
x.append(int(b))
minset = []
maxset = []
for i in range(0, N):
wrong = False
if s[i] == "a":
if len(minset) == 0:
heapq.heappush(minset,-x[i])
else:
if x[i] > minset[0]:
heapq.heappush(maxset, x[i])
else:
heapq.heappush(minset, -x[i])
fix(minset, maxset)
elif s[i] == "r":
if -x[i] in minset:
minset.remove(-x[i])
heapq.heapify(minset)
elif x[i] in maxset:
maxset.remove(x[i])
heapq.heapify(maxset)
else:
wrong = True
fix(minset, maxset)
if len(minset) == 0 and len(maxset) == 0:
wrong = True
if wrong == False:
#Calculate median
if len(minset) > len(maxset):
item = - minset[0]
print int(item)
else:
item = ((-float(minset[0])) + float(maxset[0])) / 2
if item.is_integer():
print int(item)
continue
out = str(item)
out.rstrip('0')
print out
else:
print "Wrong!"
Your original was not so legible, so first I made it object-oriented:
MedianHeapq supports methods rebalance(), add(), remove(), size(), median(). We seriously want to hide the members minset,maxset from the client code, for all sorts of sensible reasons: prevent client from swapping them, modifying them etc. If client needs to see them you just write an accessor.
We also added a __str__() method which we will use to debug visually and make your life easier.
Also added legibility changes to avoid the indexing with [i] everywhere, rename s,x arrays to op,val, add prompts on the raw_input(), reject invalid ops at the input stage.
Your actual computation of the median confuses me (when do you want float and when integer? the rstrip('0') is a bit wack), so I rewrote it, change that if you want something else.
A discussion of the algorithm is here.
Now it is legible and self-contained. Also makes it testable.
You might be making sign errors in your code, I don't know, I'll look at that later.
Next we will want to automate it by writing some PyUnit testcases. doctest is also a possibility. TBC.
Ok I think I see a bug in the sloppiness about locating the median. Remember the minset and maxset can have a size mismatch of +/-1. So take more care about precisely where the median is located.
#!/bin/python
import heapq
class MedianHeapq(object):
def __init__(self):
self.minset = []
self.maxset = []
def rebalance(self):
size_imbalance = len(self.maxset) - len(self.minset)
if len(self.maxset) > len(self.minset):
#if size_imbalance > 0:
item = heapq.heappop(self.maxset)
heapq.heappush(self.minset, -item)
#elif size_imbalance < -1:
elif len(self.minset) > (len(self.maxset) + 1):
item = heapq.heappop(self.minset)
heapq.heappush(self.maxset, -item)
def add(self, value, verbose=False):
if len(self.minset) == 0:
heapq.heappush(self.minset,-value)
else:
if value > self.minset[0]:
heapq.heappush(self.maxset, value)
else:
heapq.heappush(self.minset, -value)
self.rebalance()
if verbose: print self.__str__()
return False
def remove(self,value,verbose=False):
wrong = False
if -value in self.minset:
minset.remove(-value)
heapq.heapify(self.minset)
elif value in maxset:
maxset.remove(value)
heapq.heapify(self.maxset)
else:
wrong = True
self.rebalance()
if verbose: print self.__str__()
return wrong
def size(self):
return len(self.minset)+len(self.maxset)
def median(self):
if len(self.minset) > len(self.maxset):
item = - self.minset[0]
return int(item)
else:
item = (-self.minset[0] + self.maxset[0]) / 2.0
# Can't understand the intent of your code here: int, string or float?
if item.is_integer():
return int(item)
# continue # intent???
else:
return item
# The intent of this vv seems to be round floats and return '%.1f' % item ??
#out = str(item)
#out.rstrip('0') # why can't you just int()? or // operator?
#return out
def __str__(self):
return 'Median: %s Minset:%s Maxset:%s' % (self.median(), self.minset,self.maxset)
# Read size and elements from stdin
N = int(raw_input('Size of heap? '))
op = []
val = []
while(len(val)<N):
tmp = raw_input('a/r value : ')
op_, val_ = tmp.split(' ')
if op_ not in ['a','r']: # reject invalid ops
print 'First argument (operation) must be a:Add or r:Remove! '
continue
op.append(op_)
val.append(int(val_))
mhq = MedianHeapq()
for op_,val_ in zip(op,val): # use zip to avoid indexing with [i] everywhere
wrong = False
if op_ == 'a':
wrong = mhq.add(val_)
elif op_ == 'r':
wrong = mhq.remove(val_)
assert (mhq.size()>0), 'Heap has zero size!'
assert (not wrong), 'Heap structure is wrong!'
if not wrong:
print mhq.__str__()