Python Git diff 解析器

Question

我想用 Python 代码解析 git diff，并且我有兴趣从 diff 解析器获取以下信息：

1. 删除/添加行的内容以及行号。
2. 文件名。
3. 文件的状态，无论是删除、重命名还是添加。

我正在使用 unidiff 0.5.2 为此目的，我编写了以下代码：

from unidiff import PatchSet
import git
import os

commit_sha1 = 'b4defafcb26ab86843bbe3464a4cf54cdc978696'
repo_directory_address = '/my/git/repo'
repository = git.Repo(repo_directory_address)
commit = repository.commit(commit_sha1)
diff_index = commit.diff(commit_sha1+'~1', create_patch=True)
diff_text = reduce(lambda x, y: str(x)+os.linesep+str(y), diff_index).split(os.linesep)
patch = PatchSet(diff_text)
print patch[0].is_added_file

我正在使用 GitPython 生成 Git diff。我收到上述代码的以下错误：

current_file = PatchedFile(source_file, target_file,
UnboundLocalError: local variable 'source_file' referenced before assignment

如果您能帮助我修复此错误，我将不胜感激。

Answer 1

更新：
我发现我的旧答案不再有效。这是新的解决方案：
对于此解决方案，您需要 git 和 unidiff 软件包。

import git
from unidiff import PatchSet

from cStringIO import StringIO

commit_sha1 = 'commit_sha'
repo_directory_address = "your/repo/address"

repository = git.Repo(repo_directory_address)
commit = repository.commit(commit_sha1)

uni_diff_text = repository.git.diff(commit_sha1+ '~1', commit_sha1,
                                    ignore_blank_lines=True, 
                                    ignore_space_at_eol=True)

patch_set = PatchSet(StringIO(uni_diff_text), encoding='utf-8')

change_list = []  # list of changes 
                  # [(file_name, [row_number_of_deleted_line],
                  # [row_number_of_added_lines]), ... ]

for patched_file in patch_set:
    file_path = patched_file.path  # file name
    print('file name :' + file_path)
    del_line_no = [line.target_line_no 
                   for hunk in patched_file for line in hunk 
                   if line.is_added and
                   line.value.strip() != '']  # the row number of deleted lines
    print('deleted lines : ' + str(del_line_no))
    ad_line_no = [line.source_line_no for hunk in patched_file 
                  for line in hunk if line.is_removed and
                  line.value.strip() != '']   # the row number of added liens
    print('added lines : ' + str(ad_line_no))
    change_list.append((file_path, del_line_no, ad_line_no))

---

旧解决方案（此解决方案可能不再有效）

终于，我找到了解决办法。 gitpython 的输出与标准 git diff 输出有点不同。在标准 git diff 源文件中以 --- 开头，但 gitpython 的输出以 -------- 开头，正如您在运行以下 python 代码的输出中看到的那样（此示例是用 生成的） Elasticsearch 存储库）：

import git

repo_directory_address = '/your/elasticsearch/repository/address'
revision = "ace83d9d2a97cfe8a8aa9bdd7b46ce71713fb494"
repository = git.Repo(repo_directory_address)
commit = repository.commit(rev=revision)
# Git ignore white space at the end of line, empty lines,
# renamed files and also copied files
diff_index = commit.diff(revision+'~1', create_patch=True, ignore_blank_lines=True, 
                         ignore_space_at_eol=True, diff_filter='cr')

print reduce(lambda x, y: str(x)+str(y), diff_index)

部分输出如下：

core/src/main/java/org/elasticsearch/action/index/IndexRequest.java
=======================================================
lhs: 100644 | f8b0ce6c13fd819a02b1df612adc929674749220
rhs: 100644 | b792241b56ce548e7dd12ac46068b0bcf4649195
------ a/core/src/main/java/org/elasticsearch/action/index/IndexRequest.java
+++ b/core/src/main/java/org/elasticsearch/action/index/IndexRequest.java
@@ -20,16 +20,18 @@
package org.elasticsearch.action.index;

 import org.elasticsearch.ElasticsearchGenerationException;
+import org.elasticsearch.Version;
 import org.elasticsearch.action.ActionRequestValidationException;
 import org.elasticsearch.action.DocumentRequest;
 import org.elasticsearch.action.RoutingMissingException;
 import org.elasticsearch.action.TimestampParsingException;
 import org.elasticsearch.action.support.replication.ReplicationRequest;
 import org.elasticsearch.client.Requests;
+import org.elasticsearch.cluster.metadata.IndexMetaData;
 import org.elasticsearch.cluster.metadata.MappingMetaData;
 import org.elasticsearch.cluster.metadata.MetaData;
 import org.elasticsearch.common.Nullable;
-import org.elasticsearch.common.UUIDs;
+import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.bytes.BytesArray;
 import org.elasticsearch.common.bytes.BytesReference;

如您所见，源文件的第 4 行以 ------ 开头。要解决此问题，您需要编辑 unidiff 0.5.2 源文件中的正则表达式，该文件位于 /unidiff/constants.py 中：

RE_SOURCE_FILENAME = re.compile(
                      r'^--- (?P<filename>[^\t\n]+)(?:\t(?P<timestamp>[^\n]+))?')

至：

RE_SOURCE_FILENAME = re.compile(
                   r'^------ (?P<filename>[^\t\n]+)(?:\t(?P<timestamp>[^\n]+))?')

PS：如果源文件重命名，gitpython会生成以---开头的diff。但它不会抛出错误，因为我过滤了重命名文件的 git diff (diff_filter='cr')。

Answer 2

按照 tdihp 的建议使用 diff_index[i].diff ，并将源文件和目标文件行添加到 diff 中，否则 unidiff 将抛出异常。这是我的工作代码示例：

diffs = []
diff_index = commit.diff(prev_commit, create_patch=True)
for diff in diff_index.iter_change_type('M'):
  if diff.a_path[-3:] == ".js":
    diffs.append(diff)

if diffs:
  for d in diffs:
    a_path = "--- " + d.a_rawpath.decode('utf-8')
    b_path = "+++ " + d.b_rawpath.decode('utf-8')

    # Get detailed info
    patch = PatchSet(a_path + os.linesep + b_path + os.linesep + d.diff.decode('utf-8'))

    for h in patch[0]:
      for l in h:
        print("  " + str(l.source_line_no) + " <-> " + str(l.target_line_no))
      print("")