问题
the following takes in two strings, compares differences and return them both as identicals as well as their differences, separated by spaces (maintaining the length of the longest sting.
The commented area in the code, are the 4 strings that should be returned.
from difflib import SequenceMatcher
t1 = 'betty: backstreetvboysareback"give.jpg"LAlarrygarryhannyhref="ang"_self'
t2 = 'bettyv: backstreetvboysareback"lifeislike"LAlarrygarryhannyhref="in.php"_self'
#t1 = 'betty : backstreetvboysareback" i e "LAlarrygarryhannyhref=" n "_self'
#t2 = 'betty : backstreetvboysareback" i e "LAlarrygarryhannyhref=" n "_self'
#o1 = ' g v .jpg g '
#o2 = ' v l f islike i .php '
matcher = SequenceMatcher(None, t1, t2)
blocks = matcher.get_matching_blocks()
bla1 = []
bla2 = []
for i in range(len(blocks)):
if i != len(blocks)-1:
bla1.append([t1[blocks[i].a + blocks[i].size:blocks[i+1].a], blocks[i].a + blocks[i].size, blocks[i+1].a])
bla2.append([t2[blocks[i].b + blocks[i].size:blocks[i+1].b], blocks[i].b + blocks[i].size, blocks[i+1].b])
cnt = 0
for i in range(len(bla1)):
if bla1[i][1] < bla2[i][1]:
num = bla2[i][1] - bla1[i][1]
t2 = t2[0:bla2[i][1]] + ' '*num + t2[bla2[i][1]:len(t2)]
bla2[i][0] = ' '*num + bla2[i][0]
bla2[i][1] = bla1[i][1]
if bla2[i][1] < bla1[i][1]:
num = bla1[i][1] - bla2[i][1]
t1 = t1[0:bla1[i][1]] + ' '*num + t1[bla1[i][1]:len(t1)]
bla1[i][0] = ' '*num + bla1[i][0]
bla1[i][1] = bla2[i][1]
if bla1[i][2] > bla2[i][2]:
num = bla1[i][2] - bla2[i][2]
t2 = t2[0:bla2[i][2]] + ' '*num + t2[bla2[i][2]:len(t2)]
bla2[i][0] = bla2[i][0] + ' '*num
bla2[i][2] = bla1[i][2]
if bla2[i][2] > bla1[i][2]:
num = bla2[i][2] - bla1[i][2]
t1 = t1[0:bla1[i][2]] + ' '*num + t1[bla1[i][2]:len(t1)]
bla1[i][0] = bla1[i][0] + ' '*num
bla1[i][2] = bla2[i][2]
t11 = []
t11 = t1[0:bla1[0][1]]
t11 += t1[bla1[0][2]:bla1[1][1]]
t11 += t1[bla1[1][2]:bla1[2][1]]
t11 += t1[bla1[2][2]:bla1[3][1]]
t11 += t1[bla1[3][2]:bla1[4][1]]
t11 += t1[bla1[5][2]:bla1[6][1]]
t11 += t1[bla1[6][2]:len(t1)]
t12 = []
t12 = t2[0:bla1[0][1]]
t12 += t2[bla1[0][2]:bla1[1][1]]
t12 += t2[bla1[1][2]:bla1[2][1]]
t12 += t2[bla1[2][2]:bla1[3][1]]
t12 += t2[bla1[3][2]:bla1[4][1]]
t12 += t2[bla1[5][2]:bla1[6][1]]
t12 += t2[bla1[6][2]:len(t2)]
After ranging the blocks into an organised format bla1, bla2 where each difference is stored as a string with its start and end position eg ['v', 33, 34] for each separate string. After this, I attempt to insert spaces to match the length and separation factors necessary and this is where the code starts to break.
Please if someone could take a look!
回答1:
I have worked through resolving this, and since no one has posted a response I will post the progress and solution. The following code is progress ... it worked well when dealing with variations that had less offset but began to break when getting into larger differences, specifically in maintaining spacing (offset) in matching up the two.
from difflib import SequenceMatcher
import pdb
t1 = 'betty: backstreetvboysareback"give.jpg"LAlarrygarryhannyhref="ang"_self'
t2 = 'betty: backstreetvboysareback"lol.jpg"LAlarrygarryhannyhref="ang"_self'
#t2 = 'bettyv: backstreetvboysareback"lifeislike"LAlarrygarryhannyhref="in.php"_selff'
#t2 = 'LA'
#t2 = 'c give.'
#t2 = 'give.'
#t1 = 'betty : backstreetvboysareback" i e "LAlarrygarryhannyhref=" n "_self'
#t2 = 'betty : backstreetvboysareback" i e "LAlarrygarryhannyhref=" n "_self'
#o1 = ' g v .jpg g '
#o2 = ' v l f islike i .php '
matcher = SequenceMatcher(None, t1, t2)
blocks = matcher.get_matching_blocks()
#print(len(blocks))
bla1 = []
bla2 = []
#bla = (string), (first pos), (second pos), (pos1 + pos2), (pos + pos2 total positions added togeather)
dnt = False
for i in range(len(blocks)):
if i == 0:
if blocks[i].a != 0 and dnt == False:
bla1.append([t1[blocks[i].a:blocks[i].b], 0, blocks[i].a, 0, 0])
bla2.append([t2[blocks[i].a:blocks[i].b], 0, blocks[i].b, 0, 0])
dnt = True
if blocks[i].b != 0 and dnt == False:
bla2.append([t2[blocks[i].a:blocks[i].b], 0, blocks[i].b, 0, 0])
bla1.append([t1[blocks[i].a:blocks[i].b], 0, blocks[i].a, 0, 0])
dnt = True
if i != len(blocks)-1:
print(blocks[i])
bla1.append([t1[blocks[i].a + blocks[i].size:blocks[i+1].a], blocks[i].a + blocks[i].size, blocks[i+1].a, 0, 0])
bla2.append([t2[blocks[i].b + blocks[i].size:blocks[i+1].b], blocks[i].b + blocks[i].size, blocks[i+1].b, 0, 0])
#pdb.set_trace()
ttl = 0
for i in range(len(bla1)):
cnt = bla1[i][2] - bla1[i][1]
if cnt != 0:
bla1[i][3] = cnt
ttl = ttl + cnt
bla1[i][4] = ttl
ttl = 0
for i in range(len(bla2)):
cnt = bla2[i][2] - bla2[i][1]
if cnt != 0:
bla2[i][3] = cnt
ttl = ttl + cnt
bla2[i][4] = ttl
print(bla1)
print(bla2)
tt1 = ''
dif = 0
i = 0
while True:
if i == 0:
if bla1[i][3] >= bla2[i][3]: dif = bla1[i][3]
if bla1[i][3] < bla2[i][3]: dif = bla2[i][3]
tt1 += t1[:bla1[i][1]] + '_'*dif
if i <= len(bla1) -1:
if bla1[i][3] >= bla2[i][3]: dif = bla1[i][3]
if bla1[i][3] < bla2[i][3]: dif = bla2[i][3]
if len(bla1) != 1:
if i == 0: tt1 += t1[bla1[i][1] + bla1[i][3]:bla1[i+1][1]]
if i != 0 and i != len(bla1)-1: tt1 += '_'*dif + t1[bla1[i][1] + bla1[i][3]:bla1[i+1][1]]
if i == len(bla1)-1: tt1 += '_'*dif + t1[bla1[i][1] + bla1[i][3]:len(t1)]
i = i+1
print('t1 = ' + tt1)
else:
break
tt2 = ''
i = 0
dif = 0
while True:
if i == 0:
if bla1[i][3] >= bla2[i][3]: dif = bla1[i][3]
if bla1[i][3] < bla2[i][3]: dif = bla2[i][3]
tt2 += t2[:bla2[i][1]] + '_'*dif
if i <= len(bla2) -1:
if bla1[i][3] >= bla2[i][3]: dif = bla1[i][3]
if bla1[i][3] < bla2[i][3]: dif = bla2[i][3]
if len(bla2) != 1:
if i == 0: tt2 += t2[bla2[i][1] + bla2[i][3]:bla2[i+1][1]]
if i != 0 and i != len(bla1)-1: tt2 += '_'*dif + t2[bla2[i][1] + bla2[i][3]:bla2[i+1][1]]
if i == len(bla2)-1: tt2 += '_'*dif + t2[bla2[i][1] + bla2[i][3]:len(t2)]
i = i+1
print('t2 = ' + tt2)
else:
break
print()
Solution:
Unfortunately I have been too busy to continue coding this and have resorted to sub-processing diffutils ... this is a wonderful alternative to a lot of painstaking coding!
来源：https://stackoverflow.com/questions/48859026/python3-difflib-sequencematcher