difflib — 序列比较

# difflib_data.py
text1 = """Lorem ipsum dolor sit amet, consectetuer adipiscing
elit. Integer eu lacus accumsan arcu fermentum euismod. Donec
pulvinar porttitor tellus. Aliquam venenatis. Donec facilisis
pharetra tortor.  In nec mauris eget magna consequat
convalis. Nam sed sem vitae odio pellentesque interdum. Sed
consequat viverra nisl. Suspendisse arcu metus, blandit quis,
rhoncus ac, pharetra eget, velit. Mauris urna. Morbi nonummy
molestie orci. Praesent nisi elit, fringilla ac, suscipit non,
tristique vel, mauris. Curabitur vel lorem id nisl porta
adipiscing. Suspendisse eu lectus. In nunc. Duis vulputate
tristique enim. Donec quis lectus a justo imperdiet tempus."""

text1_lines = text1.splitlines()

text2 = """Lorem ipsum dolor sit amet, consectetuer adipiscing
elit. Integer eu lacus accumsan arcu fermentum euismod. Donec
pulvinar, porttitor tellus. Aliquam venenatis. Donec facilisis
pharetra tortor. In nec mauris eget magna consequat
convalis. Nam cras vitae mi vitae odio pellentesque interdum. Sed
consequat viverra nisl. Suspendisse arcu metus, blandit quis,
rhoncus ac, pharetra eget, velit. Mauris urna. Morbi nonummy
molestie orci. Praesent nisi elit, fringilla ac, suscipit non,
tristique vel, mauris. Curabitur vel lorem id nisl porta
adipiscing. Duis vulputate tristique enim. Donec quis lectus a
justo imperdiet tempus.  Suspendisse eu lectus. In nunc."""

text2_lines = text2.splitlines()

比较的文本

# difflib_differ.py
import difflib
from difflib_data import *

d = difflib.Differ()
diff = d.compare(text1_lines, text2_lines)
print('\n'.join(diff))

其他输出格式

difflib_unified.py
import difflib
from difflib_data import *

diff = difflib.unified_diff(
    text1_lines,
    text2_lines,
    lineterm='',
)
print('\n'.join(diff))

垃圾数据

# difflib_junk.py
# This example is adapted from the source for difflib.py.

from difflib import SequenceMatcher


def show_results(match):
    print('  a    = {}'.format(match.a))
    print('  b    = {}'.format(match.b))
    print('  size = {}'.format(match.size))
    i, j, k = match
    print('  A[a:a+size] = {!r}'.format(A[i:i + k]))
    print('  B[b:b+size] = {!r}'.format(B[j:j + k]))


A = " abcd"
B = "abcd abcd"

print('A = {!r}'.format(A))
print('B = {!r}'.format(B))

print('\nWithout junk detection:')
s1 = SequenceMatcher(None, A, B)
match1 = s1.find_longest_match(0, len(A), 0, len(B))
show_results(match1)

print('\nTreat spaces as junk:')
s2 = SequenceMatcher(lambda x: x == " ", A, B)
match2 = s2.find_longest_match(0, len(A), 0, len(B))
show_results(match2)

比较任意类型

# difflib_seq.py
import difflib

s1 = [1, 2, 3, 5, 6, 4]
s2 = [2, 3, 5, 4, 6, 1]

print('Initial data:')
print('s1 =', s1)
print('s2 =', s2)
print('s1 == s2:', s1 == s2)
print()

matcher = difflib.SequenceMatcher(None, s1, s2)
for tag, i1, i2, j1, j2 in reversed(matcher.get_opcodes()):

    if tag == 'delete':
        print('Remove {} from positions [{}:{}]'.format(
            s1[i1:i2], i1, i2))
        print('  before =', s1)
        del s1[i1:i2]

    elif tag == 'equal':
        print('s1[{}:{}] and s2[{}:{}] are the same'.format(
            i1, i2, j1, j2))

    elif tag == 'insert':
        print('Insert {} from s2[{}:{}] into s1 at {}'.format(
            s2[j1:j2], j1, j2, i1))
        print('  before =', s1)
        s1[i1:i2] = s2[j1:j2]

    elif tag == 'replace':
        print(('Replace {} from s1[{}:{}] '
               'with {} from s2[{}:{}]').format(
                   s1[i1:i2], i1, i2, s2[j1:j2], j1, j2))
        print('  before =', s1)
        s1[i1:i2] = s2[j1:j2]

    print('   after =', s1, '\n')

print('s1 == s2:', s1 == s2)