'python how to record the number of elements in listA that appear in the same order as in listB
I am trying to trace to what extent is listA, listB, listC... similar to the original list. How do I print the number of elements that occur in the same sequence in listA as they occur in the original list?
original_list = ['I', 'live', 'in', 'space', 'with', 'my', 'dog']
listA = ['my', 'name', 'my', 'dog', 'is', 'two', 'years', 'old']
listB = ['how', 'where', 'I', 'live', 'in', 'space', 'with']
listC = ['I', 'live', 'to', 'the' 'in', 'space', 'with', 'my', 'football', 'my','dog']
Output:
listA: Count = 2 #'my', 'dog'
listB: Count = 5 #'I', 'live', 'in', 'space', 'with'
listC: Count = 2,4,2 #'I', 'live'
#'in', 'space', 'with', 'my'
#'my', 'dog'
Solution 1:[1]
I wrote a function that does the job I think. It might be a bit too complex, but I can't see an easier way at the moment:
original = ['I', 'live', 'in', 'space', 'with', 'my', 'dog']
listA = ['my', 'name', 'my', 'dog', 'is', 'two', 'years', 'old']
listB = ['how', 'where', 'I', 'live', 'in', 'space', 'with']
listC = ['I', 'live', 'to', 'the', 'in', 'space', 'with', 'my', 'football', 'my', 'dog']
def get_sequence_lengths(original_list, comparative_list):
original_options = []
for i in range(len(original_list)):
for j in range(i + 1, len(original_list)):
original_options.append(original_list[i:j + 1])
comparative_options = []
for i in range(len(comparative_list)):
for j in range(i+1, len(comparative_list)):
comparative_options.append(comparative_list[i:j+1])
comparative_options.sort(key=len, reverse=True)
matches = []
while comparative_options:
for option in comparative_options:
if option in original_options:
matches.append(option)
new_comparative_options = comparative_options.copy()
for l in comparative_options:
counter = 0
for v in option:
counter = counter + 1 if v in l else 0
if counter == len(l):
new_comparative_options.remove(l)
break
comparative_options = new_comparative_options
break
if option == comparative_options[-1]:
break
matches = [option for option in original_options if option in matches]
lengths = [len(option) for option in matches]
print(lengths)
print(matches)
return lengths
If you call it with the original list and example lists, it prints the following.get_sequence_lengths(original, listA) prints [2] [['my', 'dog']].
get_sequence_lengths(original, listB) prints [5] [['I', 'live', 'in', 'space', 'with']].
get_sequence_lengths(original, listC) prints [2, 4, 2] [['I', 'live'], ['in', 'space', 'with', 'my'], ['my', 'dog']].
Solution 2:[2]
EDITED
I found this problem fun to do and wanted to explore some other options from the accepted one.
def _get_sequences(inter_dict : dict, list_range : int) -> tuple[set, int]:
occuring = [0] * list_range
for key, indices in inter_dict.items(): # lays out intersecting strings as they occur
for idx in indices:
occuring[idx] = key
_temp_list = []
lengths = []
matches = []
for idx in range(len(occuring)):
item = occuring.pop(0)
if item != 0: # if on python 3.8+ you could use (( item := occuring.pop(0) ) != 0) instead
_temp_list.append(item)
elif (bool(_temp_list) and len(_temp_list) > 1):
matches.append( _temp_list.copy() )
lengths.append( len(_temp_list) )
_temp_list.clear()
elif (bool(_temp_list) and item == 0) and len(_temp_list) == 1: # if its a single occurrence ignore
_temp_list.clear()
if bool(_temp_list) and len(_temp_list) > 1: # ensures no matching strings are missed
matches.append( _temp_list )
lengths.append( len(_temp_list) )
return lengths, matches
def get_intersecting(list_a, list_b) -> tuple[set, int]:
intersecting = set(list_a) & set(list_b) # returns intersecting strings
indices_dict = {}
for item in intersecting:
indices = [ index for index, value in enumerate(list_b) if value == item ] # gets occuring indices of each string
indices_dict[item] = indices
return _get_sequences( indices_dict, len(list_b) )
if __name__ == "__main__":
original = ['I', 'live', 'in', 'space', 'with', 'my', 'dog']
listA = ['my', 'name', 'my', 'dog', 'is', 'two', 'years', 'old']
listB = ['how', 'where', 'I', 'live', 'in', 'space', 'with']
listC = ['I', 'live', 'to', 'the', 'in', 'space', 'with', 'my', 'football', 'my', 'dog']
lengths, matches = get_intersecting(original, listA)
print(lengths, matches) # [2] [['my', 'dog']]
lengths, matches = get_intersecting(original, listB)
print(lengths, matches) # [5] [['I', 'live', 'in', 'space', 'with']]
lengths, matches = get_intersecting(original, listC)
print(lengths, matches) # [2, 4, 2] [['I', 'live'] ['in', 'space', 'with', 'my'] ['my', 'dog']]
EDITED x2 This would probably be my final solution.
def ordered_intersecting(list_a, list_b) -> tuple[int, list]:
matches = []
for item in list_b:
if item in list_a: # while iterating we can just add them to a return list as they appear
matches.append(item)
elif len(matches) > 1: # once we come across an item that does not intersect we know we can yield a return value ( as long as matches are greater than 1 )
yield len(matches), matches.copy() ; matches.clear() # a shallow copy should be good enough, but if needed it can be changed to a deep one
if len(matches) > 1: # catch any remaining matches
yield len(matches), matches
if __name__ == "__main__":
original = ['I', 'live', 'in', 'space', 'with', 'my', 'dog']
listA = ['my', 'name', 'my', 'dog', 'is', 'two', 'years', 'old']
listB = ['how', 'where', 'I', 'live', 'in', 'space', 'with']
listC = ['I', 'live', 'to', 'the', 'in', 'space', 'with', 'my', 'football', 'my', 'dog']
print( list(ordered_intersecting(original, listA)) )
print( list(ordered_intersecting(original, listB)) )
print( list(ordered_intersecting(original, listC)) )
Sources
This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.
Source: Stack Overflow
| Solution | Source |
|---|---|
| Solution 1 | davidlucius |
| Solution 2 |
