No errors, just doesn't print or do anything - python

I am pretty a beginner and I'm looking for help. I am supposed to write a simple programm which reads numbers from a file (they are ordered in two columns like this:
3 788506
255 879405
3 687899
255 697879 etc)
and always pairwise subtracts the number near 255 from the number near 3. The differences should be appended to a list. I also have to check whether the pair is rigt (e.g. that it's always 3 and 255 one after the other and not two 255s). So far I think I'm ready, but it doesn't do anything. I spent hours looking for my mistake, but I just cannot see what went wrong. I would appreciate any help.
filepath = "C:/liz/RT1-1.dat"
f = open (filepath, 'rU')
reac3 = []
reac255 = []
right_list = []
wrong_list = []
very_wrong_list =[]
li = [i.strip().split() for i in f.readlines()]
for element in li:
if int(element[0]) == 3: reac3.append(element[-1])
elif int(element[0]) == 255: reac255.append(element[-1])
k = 0
for i in range (0, len(li)+1, 2): #0,2,4,6,8 etc
if li[i][0] == 3 and li[i+1][0] == 255:
difference = int(reac255[k]) - int(reac3[k])
print int(difference)
k+=1
if difference > 300 and difference < 1200: right_list.append(difference)
else: wrong_list.append(difference)
else: very_wrong_list.append(li[i])
print right_list

i.strip().split() will return 2 strings .. therefore your comparison li[i][0] == 3 & li[i+1][0] == 5 should fail as li[i][0] & li[i+1][0] are still strings.
Also notice, that since len(li) should be even, then xrange(0, len(li) + 1, 2) will eventually make i = len(li) which should be out of the list boundaries.

Related

Intersection of lists having comparing 3 elements at a time

I have tried creating two separate lists by the name of 'sample' and 'game'. These contain outcomes of 3 games, eg, (1,1,0) (0,1,0) shown as [1,1,0,0,1,0] in both of the lists. I am trying to find intersection between both the lists through my last loop which should compare 3 elements of one list with 3 elements of another list and then return the match by appending it to list 'intersection'.
Eg, sample has [1,1,0,0,1,0] and game has [1,0,1,1,1,0,1,1,0]. The intersection of both should give me [1,1,0] that is the first 3 elements of 'sample' and 3 elements from index 3 of 'game'.
However, I am facing an error of index out of range.
Also, (1,1,0) in one list might get compared with the same (1,1,0) in other list twice, if that other list has (1,1,0) 2 times, which should not happen in intersection.
import random
P1 = 1/2 # win 1st game
P2 = 2/3 # win game immediately after a win
P3 = 1/3 # win game immediately after a loss
A = [0,1] # 0 for losing a game and 1 for winning a game
N = 100
sample_points = []; G1=[]; G2=[]; G3=[]
for i in range(N):
Game1 = random.choice([0,1])
Game2 = random.choice([0,1])
Game3 = random.choice([0,1])
G1.append(Game1)
G2.append(Game2)
G3.append(Game3)
sample_points.extend([Game1, Game2, Game3])
sample = []; game=[];intersection=[]
i = 0
# creating two separate lists
while i < len(sample_points):
if sample_points[i] + sample_points[i+1] + sample_points[i+2] == 2:
n1 = sample_points[i] ; n2 = sample_points[i+1] ; n3 = sample_points[i+2]
sample.append(n1);sample.append(n2);sample.append(n3)
if sample_points[i] == 1:
q1 = sample_points[i] ; q2 = sample_points[i+1] ; q3 = sample_points[i+2]
game.append(q1);game.append(q2);game.append(q3)
i = i+3
i=0
j=0
while j < len(sample):
for i in range(len(game)):
for j in range(len(sample)):
if game[i] == sample[j] and game[i+1] == sample[j+1] and game[i+2] == sample[j+2]:
intersection.append(sample[j]);intersection.append(sample[j+1]);intersection.append(sample[j+2])
j = j+3
i=i+3
Let's look at this block of code
while j < len(sample):
for i in range(len(game)):
for j in range(len(sample)):
if game[i] == sample[j] and game[i+1] == sample[j+1] and game[i+2] == sample[j+2]:
intersection.append(sample[j]);intersection.append(sample[j+1]);intersection.append(sample[j+2])
j = j+3
i=i+3
Notice the you let i and j to run until the very end of the vector and yet you consider indices like i+1 and i+2.
I would use range to indicate the increment by 3 and also we can compare two lists rather than using multiple and statement. I have also tried to use extend. You might like to replace it with something like
for i in range(0, len(game)-3, 3):
for j in range(0, len(sample)-3, 3):
if game[i:i+3] == sample[j:j+3]:
intersection.extend(sample[j:j+3])
print(intersection)
Also, you mentioned that you want to avoid duplicate, you might want to use set to check for duplicate for the two separate lists and then convert them back to a list.

How to get the correct number of distinct combination locks with a margin or error of +-2?

I am trying to solve the usaco problem combination lock where you are given a two lock combinations. The locks have a margin of error of +- 2 so if you had a combination lock of 1-3-5, the combination 3-1-7 would still solve it.
You are also given a dial. For example, the dial starts at 1 and ends at the given number. So if the dial was 50, it would start at 1 and end at 50. Since the beginning of the dial is adjacent to the end of the dial, the combination 49-1-3 would also solve the combination lock of 1-3-5.
In this program, you have to output the number of distinct solutions to the two lock combinations. For the record, the combination 3-2-1 and 1-2-3 are considered distinct, but the combination 2-2-2 and 2-2-2 is not.
I have tried creating two functions, one to check whether three numbers match the constraints of the first combination lock and another to check whether three numbers match the constraints of the second combination lock.
a,b,c = 1,2,3
d,e,f = 5,6,7
dial = 50
def check(i,j,k):
i = (i+dial) % dial
j = (j+dial) % dial
k = (k+dial) % dial
if abs(a-i) <= 2 and abs(b-j) <= 2 and abs(c-k) <= 2:
return True
return False
def check1(i,j,k):
i = (i+dial) % dial
j = (j+dial) % dial
k = (k+dial) % dial
if abs(d-i) <= 2 and abs(e-j) <= 2 and abs(f-k) <= 2:
return True
return False
res = []
count = 0
for i in range(1,dial+1):
for j in range(1,dial+1):
for k in range(1,dial+1):
if check(i,j,k):
count += 1
res.append([i,j,k])
if check1(i,j,k):
count += 1
res.append([i,j,k])
print(sorted(res))
print(count)
The dial is 50 and the first combination is 1-2-3 and the second combination is 5-6-7.
The program should output 249 as the count, but it instead outputs 225. I am not really sure why this is happening. I have added the array for display purposes only. Any help would be greatly appreciated!
You're going to a lot of trouble to solve this by brute force.
First of all, your two check routines have identical functionality: just call the same routine for both combinations, giving the correct combination as a second set of parameters.
The critical logic problem is handling the dial wrap-around: you miss picking up the adjacent numbers. Run 49 through your check against a correct value of 1:
# using a=1, i=49
i = (1+50)%50 # i = 1
...
if abs(1-49) <= 2 ... # abs(1-49) is 48. You need it to show up as 2.
Instead, you can check each end of the dial:
a_diff = abs(i-a)
if a_diff <=2 or a_diff >= (dial-2) ...
Another way is to start by making a list of acceptable values:
a_vals = [(a-oops) % dial] for oops in range(-2, 3)]
... but note that you have to change the 0 value to dial. For instance, for a value of 1, you want a list of [49, 50, 1, 2, 3]
With this done, you can check like this:
if i in a_vals and j in b_vals and k in c_vals:
...
If you want to upgrade to the itertools package, you can simply generate all desired combinations:
combo = set(itertools.product(a_list, b_list_c_list) )
Do that for both given combinations and take the union of the two sets. The length of the union is the desired answer.
I see the follow-up isn't obvious -- at least, it's not appearing in the comments.
You have 5*5*5 solutions for each combination; start with 250 as your total.
Compute the sizes of the overlap sets: the numbers in each triple that can serve for each combination. For your given problem, those are [3],[4],[5]
The product of those set sizes is the quantity of overlap: 1*1*1 in this case.
The overlapping solutions got double-counted, so simply subtract the extra from 250, giving the answer of 249.
For example, given 1-2-3 and 49-6-6, you would get sets
{49, 50, 1}
{4}
{4, 5}
The sizes are 3, 1, 2; the product of those numbers is 6, so your answer is 250-6 = 244
Final note: If you're careful with your modular arithmetic, you can directly compute the set sizes without building the sets, making the program very short.
Here is one approach to a semi-brute-force solution:
import itertools
#The following code assumes 0-based combinations,
#represented as tuples of numbers in the range 0 to dial - 1.
#A simple wrapper function can be used to make the
#code apply to 1-based combos.
#The following function finds all combos which open lock with a given combo:
def combos(combo,tol,dial):
valids = []
for p in itertools.product(range(-tol,1+tol),repeat = 3):
valids.append(tuple((x+i)%dial for x,i in zip(combo,p)))
return valids
#The following finds all combos for a given iterable of target combos:
def all_combos(targets,tol,dial):
return set(combo for target in targets for combo in combos(target,tol,dial))
For example, len(all_combos([(0,1,2),(4,5,6)],2,50)) evaluate to 249.
The correct code for what you are trying to do is the following:
dial = 50
a = 1
b = 2
c = 3
d = 5
e = 6
f = 7
def check(i,j,k):
if (abs(a-i) <= 2 or (dial-abs(a-i)) <= 2) and \
(abs(b-j) <= 2 or (dial-abs(b-j)) <= 2) and \
(abs(c-k) <= 2 or (dial-abs(c-k)) <= 2):
return True
return False
def check1(i,j,k):
if (abs(d-i) <= 2 or (dial-abs(d-i)) <= 2) and \
(abs(e-j) <= 2 or (dial-abs(e-j)) <= 2) and \
(abs(f-k) <= 2 or (dial-abs(f-k)) <= 2):
return True
return False
res = []
count = 0
for i in range(1,dial+1):
for j in range(1,dial+1):
for k in range(1,dial+1):
if check(i,j,k):
count += 1
res.append([i,j,k])
elif check1(i,j,k):
count += 1
res.append([i,j,k])
print(sorted(res))
print(count)
And the result is 249, the total combinations are 2*(5**3) = 250, but we have the duplicates: [3, 4, 5]

Python looping through multiple lists

I've this code:
for i in range(0, len(codiceCassExcel)):
count1step += 1
for j in range(0, len(vwLinesToList)):
if data_reg[i] == vwLinesToList[j][1]:
if codiceCassExcel[i] == vwLinesToList[j][0]:
#Gestione movimento diverso da 601 e non bolle nostre
if tipo_mov[i] != 601 and len(vwLinesToList[j][7]) != 8:
count2step += 1
if ((int(qta_movimentata[i]) + int(vwLinesToList[j][4])) != 0) or ((int(-qta_movimentata[i]) + int(vwLinesToList[j][3])) != 0):
imballoColumnIn.append(vwLinesToList[j][0]),
dateColumnIn.append(vwLinesToList[j][1]),
absColumnIn.append(vwLinesToList[j][2]),
inColumnIn.append(vwLinesToList[j][3]),
outColumnIn.append(vwLinesToList[j][4]),
ddtColumnIn.append(vwLinesToList[j][7]),
wkColumnIn.append(vwLinesToList[j][8])
elif vwLinesToList[j][7] == bolla_excel[i]:
if ((int(qta_movimentata[i]) + int(vwLinesToList[j][4])) != 0) or (
(int(-qta_movimentata[i]) + int(vwLinesToList[j][3])) != 0):
imballoColumn.append(vwLinesToList[j][0]),
dateColumn.append(vwLinesToList[j][1]),
absColumn.append(vwLinesToList[j][2]),
inColumn.append(vwLinesToList[j][3]),
outColumn.append(vwLinesToList[j][4]),
ddtColumn.append(vwLinesToList[j][7]),
wkColumn.append(vwLinesToList[j][8])
I've 5 lists with hundred of items and a lists with similar items (vwLinesToLists). I want to check if:
firstListItem[i] and secondListItem[i](and so on...) is equal to
vwLinesToList[j][1], vwLinesToList[j][2], vwLinesToList[j][3]
If it's true, check if nListItem - vwLinesToList[j][6] != 0:
append each vwLinesToList[item] to separate list
I need an hint about write my code without all this nested stuff.
Thank you in advance
Use zip method to iterate over your lists. See zip lists in python for code samples.
Also consider using of izip_longest function which may be useful to...

How to cycle through the index of an array?

line 14 is where my main problem is.i need to cycle through each item in the array and use it's index to determine whether or not it is a multiple of four so i can create proper spacing for binary numbers.
def decimalToBinary(hu):
bits = []
h = []
while hu > 0:
kla = hu%2
bits.append(kla)
hu = int(hu/2)
for i in reversed(bits):
h.append(i)
if len(h) <= 4:
print (''.join(map(str,h)))
else:
for j in range(len(h)):
h.index(1) = h.index(1)+1
if h.index % 4 != 0:
print (''.join(map(str,h)))
elif h.index % 4 == 0:
print (' '.join(map(str,h)))
decimalToBinary( 23 )
If what you're looking for is the index of the list from range(len(h)) in the for loop, then you can change that line to for idx,j in enumerate(range(len(h))): where idx is the index of the range.
This line h.index(1) = h.index(1)+1 is incorrect. Modified your function, so at least it executes and generates an output, but whether it is correct, i dont know. Anyway, hope it helps:
def decimalToBinary(hu):
bits = []
h = []
while hu > 0:
kla = hu%2
bits.append(kla)
hu = int(hu/2)
for i in reversed(bits):
h.append(i)
if len(h) <= 4:
print (''.join(map(str,h)))
else:
for j in range(len(h)):
h_index = h.index(1)+1 # use h_index variable instead of h.index(1)
if h_index % 4 != 0:
print (''.join(map(str,h)))
elif h_index % 4 == 0:
print (' '.join(map(str,h)))
decimalToBinary( 23 )
# get binary version to check your result against.
print(bin(23))
This results:
#outout from decimalToBinary
10111
10111
10111
10111
10111
#output from bin(23)
0b10111
You're trying to join the bits to string and separate them every 4 bits. You could modify your code with Marcin's correction (by replacing the syntax error line and do some other improvements), but I suggest doing it more "Pythonically".
Here's my version:
def decimalToBinary(hu):
bits = []
while hu > 0:
kla = hu%2
bits.append(kla)
hu = int(hu/2)
h = [''.join(map(str, bits[i:i+4])) for i in range(0,len(bits),4)]
bu = ' '.join(h)
print bu[::-1]
Explanation for the h assignment line:
range(0,len(bits),4): a list from 0 to length of bits with step = 4, eg. [0, 4, 8, ...]
[bits[i:i+4] for i in [0, 4, 8]: a list of lists whose element is every four elements from bits
eg. [ [1,0,1,0], [0,1,0,1] ...]
[''.join(map(str, bits[i:i+4])) for i in range(0,len(bits),4)]: convert the inner list to string
bu[::-1]: reverse the string
If you are learning Python, it's good to do your way. As #roippi pointed out,
for index, value in enumerate(h):
will give you access to both index and value of member of h in each loop.
To group 4 digits, I would do like this:
def decimalToBinary(num):
binary = str(bin(num))[2:][::-1]
index = 0
spaced = ''
while index + 4 < len(binary):
spaced += binary[index:index+4]+' '
index += 4
else:
spaced += binary[index:]
return spaced[::-1]
print decimalToBinary(23)
The result is:
1 0111

Python interval interesction

My problem is as follows:
having file with list of intervals:
1 5
2 8
9 12
20 30
And a range of
0 200
I would like to do such an intersection that will report the positions [start end] between my intervals inside the given range.
For example:
8 9
12 20
30 200
Beside any ideas how to bite this, would be also nice to read some thoughts on optimization, since as always the input files are going to be huge.
this solution works as long the intervals are ordered by the start point and does not require to create a list as big as the total range.
code
with open("0.txt") as f:
t=[x.rstrip("\n").split("\t") for x in f.readlines()]
intervals=[(int(x[0]),int(x[1])) for x in t]
def find_ints(intervals, mn, mx):
next_start = mn
for x in intervals:
if next_start < x[0]:
yield next_start,x[0]
next_start = x[1]
elif next_start < x[1]:
next_start = x[1]
if next_start < mx:
yield next_start, mx
print list(find_ints(intervals, 0, 200))
output:
(in the case of the example you gave)
[(0, 1), (8, 9), (12, 20), (30, 200)]
Rough algorithm:
create an array of booleans, all set to false seen = [False]*200
Iterate over the input file, for each line start end set seen[start] .. seen[end] to be True
Once done, then you can trivially walk the array to find the unused intervals.
In terms of optimisations, if the list of input ranges is sorted on start number, then you can track the highest seen number and use that to filter ranges as they are processed -
e.g. something like
for (start,end) in input:
if end<=lowest_unseen:
next
if start<lowest_unseen:
start=lowest_unseen
...
which (ignoring the cost of the original sort) should make the whole thing O(n) - you go through the array once to tag seen/unseen and once to output unseens.
Seems I'm feeling nice. Here is the (unoptimised) code, assuming your input file is called input
seen = [False]*200
file = open('input','r')
rows = file.readlines()
for row in rows:
(start,end) = row.split(' ')
print "%s %s" % (start,end)
for x in range( int(start)-1, int(end)-1 ):
seen[x] = True
print seen[0:10]
in_unseen_block=False
start=1
for x in range(1,200):
val=seen[x-1]
if val and not in_unseen_block:
continue
if not val and in_unseen_block:
continue
# Must be at a change point.
if val:
# we have reached the end of the block
print "%s %s" % (start,x)
in_unseen_block = False
else:
# start of new block
start = x
in_unseen_block = True
# Handle end block
if in_unseen_block:
print "%s %s" % (start, 200)
I'm leaving the optimizations as an exercise for the reader.
If you make a note every time that one of your input intervals either opens or closes, you can do what you want by putting together the keys of opens and closes, sort into an ordered set, and you'll be able to essentially think, "okay, let's say that each adjacent pair of numbers forms an interval. Then I can focus all of my logic on these intervals as discrete chunks."
myRange = range(201)
intervals = [(1,5), (2,8), (9,12), (20,30)]
opens = {}
closes = {}
def open(index):
if index not in opens:
opens[index] = 0
opens[index] += 1
def close(index):
if index not in closes:
closes[index] = 0
closes[index] += 1
for start, end in intervals:
if end > start: # Making sure to exclude empty intervals, which can be problematic later
open(start)
close(end)
# Sort all the interval-endpoints that we really need to look at
oset = {0:None, 200:None}
for k in opens.keys():
oset[k] = None
for k in closes.keys():
oset[k] = None
relevant_indices = sorted(oset.keys())
# Find the clear ranges
state = 0
results = []
for i in range(len(relevant_indices) - 1):
start = relevant_indices[i]
end = relevant_indices[i+1]
start_state = state
if start in opens:
start_state += opens[start]
if start in closes:
start_state -= closes[start]
end_state = start_state
if end in opens:
end_state += opens[end]
if end in closes:
end_state -= closes[end]
state = end_state
if start_state == 0:
result_start = start
result_end = end
results.append((result_start, result_end))
for start, end in results:
print(str(start) + " " + str(end))
This outputs:
0 1
8 9
12 20
30 200
The intervals don't need to be sorted.
This question seems to be a duplicate of Merging intervals in Python.
If I understood well the problem, you have a list of intervals (1 5; 2 8; 9 12; 20 30) and a range (0 200), and you want to get the positions outside your intervals, but inside given range. Right?
There's a Python library that can help you on that: python-intervals (also available from PyPI using pip). Disclaimer: I'm the maintainer of that library.
Assuming you import this library as follows:
import intervals as I
It's quite easy to get your answer. Basically, you first want to create a disjunction of intervals based on the ones you provide:
inters = I.closed(1, 5) | I.closed(2, 8) | I.closed(9, 12) | I.closed(20, 30)
Then you compute the complement of these intervals, to get everything that is "outside":
compl = ~inters
Then you create the union with [0, 200], as you want to restrict the points to that interval:
print(compl & I.closed(0, 200))
This results in:
[0,1) | (8,9) | (12,20) | (30,200]

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