Objects

There are four types of Git objects: blobs, trees, commits and tags. For each one pygit2 has a type, and all four types inherit from the base Object type.

Object lookup

In the previous chapter we learnt about Object IDs. With an Oid we can ask the repository to get the associated object. To do that the Repository class implementes a subset of the mapping interface.

class pygit2.Repository(path=None, flags=0)
get(key, default=None)

Return the Git object for the given id, returns the default value if there’s no object in the repository with that id. The id can be an Oid object, or an hexadecimal string.

Example:

>>> from pygit2 import Repository
>>> repo = Repository('path/to/pygit2')
>>> obj = repo.get("101715bf37440d32291bde4f58c3142bcf7d8adb")
>>> obj
<_pygit2.Commit object at 0x7ff27a6b60f0>
__getitem__(id)

Return the Git object for the given id, raise KeyError if there’s no object in the repository with that id. The id can be an Oid object, or an hexadecimal string.

__contains__(id)

Returns True if there is an object in the Repository with that id, False if there is not. The id can be an Oid object, or an hexadecimal string.

The Object base type

The Object type is a base type, it is not possible to make instances of it, in any way.

It is the base type of the Blob, Tree, Commit and Tag types, so it is possible to check whether a Python value is an Object or not:

>>> from pygit2 import Object
>>> commit = repository.revparse_single('HEAD')
>>> print(isinstance(commit, Object))
True

All Objects are immutable, they cannot be modified once they are created:

>>> commit.message = u"foobar"
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: attribute 'message' of '_pygit2.Commit' objects is not writable

Derived types (blobs, trees, etc.) don’t have a constructor, this means they cannot be created with the common idiom:

>>> from pygit2 import Blob
>>> blob = Blob("data")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: cannot create '_pygit2.Blob' instances

New objects are created using an specific API we will see later.

This is the common interface for all Git objects:

class pygit2.Object

Base class for Git objects.

__eq__(value, /)

Return self==value.

__hash__()

Return hash(self).

__ne__(value, /)

Return self!=value.

__repr__()

Return repr(self).

filemode

Filemode (will be None if the object was not reached trough a tree)

id

The object id, an instance of the Oid type.

name

Name (will be None if the object was not reached trough a tree)

peel(target_type)Object

Peel the current object and returns the first object of the given type

read_raw()

Returns the byte string with the raw contents of the object.

short_id

An unambiguous short (abbreviated) hex Oid string for the object.

type

One of the GIT_OBJ_COMMIT, GIT_OBJ_TREE, GIT_OBJ_BLOB or GIT_OBJ_TAG constants.

type_str

One of the ‘commit’, ‘tree’, ‘blob’ or ‘tag’ strings.

Blobs

A blob is just a raw byte string. They are the Git equivalent to files in a filesytem.

This is their API:

class pygit2.Blob

Blob object.

Blobs implement the buffer interface, which means you can get access to its data via memoryview(blob) without the need to create a copy.

data

The contents of the blob, a byte string. This is the same as Blob.read_raw().

Example, print the contents of the .gitignore file:

>>> blob = repo['d8022420bf6db02e906175f64f66676df539f2fd']
>>> print(blob.data)
MANIFEST
build
dist
diff([blob, flag, old_as_path, new_as_path])

Directly generate a pygit2.Patch from the difference between two blobs.

Returns: Patch.

Parameters:

blobBlob

The Blob to diff.

flag

A GIT_DIFF_* constant.

old_as_pathstr

Treat old blob as if it had this filename.

new_as_pathstr

Treat new blob as if it had this filename.

diff_to_buffer([buffer, flag, old_as_path, buffer_as_path])

Directly generate a Patch from the difference between a blob and a buffer.

Returns: Patch.

Parameters:

bufferBlob

Raw data for new side of diff.

flag

A GIT_DIFF_* constant.

old_as_pathstr

Treat old blob as if it had this filename.

buffer_as_pathstr

Treat buffer as if it had this filename.

is_binary

True if binary data, False if not.

size

Size in bytes.

Example:

>>> print(blob.size)
130

Creating blobs

There are a number of methods in the repository to create new blobs, and add them to the Git object database:

class pygit2.Repository(path=None, flags=0)
create_blob(data)Oid

Create a new blob from a bytes string. The blob is added to the Git object database. Returns the oid of the blob.

Example:

>>> id  = repo.create_blob('foo bar')   # Creates blob from a byte string
>>> blob = repo[id]
>>> blob.data
'foo bar'
create_blob_fromdisk(path)Oid

Create a new blob from a file anywhere (no working directory check).

create_blob_fromiobase(io.IOBase)Oid

Create a new blob from an IOBase object.

create_blob_fromworkdir(path)Oid

Create a new blob from a file within the working directory. The given path must be relative to the working directory, if it is not an error is raised.

There are also some functions to calculate the id for a byte string without creating the blob object:

pygit2.hash(data)Oid

Returns the oid of a new blob from a string without actually writing to the odb.

pygit2.hashfile(path)Oid

Returns the oid of a new blob from a file path without actually writing to the odb.

Trees

At the low level (libgit2) a tree is a sorted collection of tree entries. In pygit2 accessing an entry directly returns the object.

A tree can be iterated, and partially implements the sequence and mapping interfaces.

class pygit2.Tree

Tree objects.

__getitem__(name)

Tree[name]

Return the Object subclass instance for the given name. Raise KeyError if there is not a tree entry with that name.

__truediv__(name)

Tree / name

Return the Object subclass instance for the given name. Raise KeyError if there is not a tree entry with that name. This allows navigating the tree similarly to Pathlib using the slash operator via.

Example:

>>> entry = tree / 'path' / 'deeper' / 'some.file'
__contains__(name)

name in Tree

Return True if there is a tree entry with the given name, False otherwise.

__len__()

len(Tree)

Return the number of objects in the tree.

__iter__()

for object in Tree

Return an iterator over the objects in the tree.

diff_to_index(index[, flags, context_lines, interhunk_lines])Diff

Show the changes between the index and a given Tree.

Parameters:

treeTree

The tree to diff.

flag

A GIT_DIFF_* constant.

context_lines

The number of unchanged lines that define the boundary of a hunk (and to display before and after).

interhunk_lines

The maximum number of unchanged lines between hunk boundaries before the hunks will be merged into a one.

diff_to_tree([tree, flags, context_lines, interhunk_lines, swap])Diff

Show the changes between two trees.

Parameters:

tree: Tree

The tree to diff. If no tree is given the empty tree will be used instead.

flag

A GIT_DIFF_* constant.

context_lines

The number of unchanged lines that define the boundary of a hunk (and to display before and after).

interhunk_lines

The maximum number of unchanged lines between hunk boundaries before the hunks will be merged into a one.

swap

Instead of diffing a to b. Diff b to a.

diff_to_workdir([flags, context_lines, interhunk_lines])Diff

Show the changes between the Tree and the workdir.

Parameters:

flag

A GIT_DIFF_* constant.

context_lines

The number of unchanged lines that define the boundary of a hunk (and to display before and after).

interhunk_lines

The maximum number of unchanged lines between hunk boundaries before the hunks will be merged into a one.

Example:

>>> tree = commit.tree
>>> len(tree)                        # Number of entries
6

>>> for obj in tree:                 # Iteration
...     print(obj.id, obj.type_str, obj.name)
...
7151ca7cd3e59f3eab19c485cfbf3cb30928d7fa blob .gitignore
c36f4cf1e38ec1bb9d9ad146ed572b89ecfc9f18 blob COPYING
32b30b90b062f66957d6790c3c155c289c34424e blob README.md
c87dae4094b3a6d10e08bc6c5ef1f55a7e448659 blob pygit2.c
85a67270a49ef16cdd3d328f06a3e4b459f09b27 blob setup.py
3d8985bbec338eb4d47c5b01b863ee89d044bd53 tree test

>>> obj = tree / 'pygit2.c'          # Get an object by name
>>> obj
<_pygit2.Blob at 0x7f08a70acc10>

Creating trees

class pygit2.Repository(path=None, flags=0)
TreeBuilder([tree])TreeBuilder

Create a TreeBuilder object for this repository.

class pygit2.TreeBuilder

TreeBuilder objects.

clear()

Clear all the entries in the builder.

get(name)Object

Return the Object for the given name, or None if there is not.

insert(name, oid, attr)

Insert or replace an entry in the treebuilder.

Parameters:

attr

Available values are GIT_FILEMODE_BLOB, GIT_FILEMODE_BLOB_EXECUTABLE, GIT_FILEMODE_TREE, GIT_FILEMODE_LINK and GIT_FILEMODE_COMMIT.

remove(name)

Remove an entry from the builder.

write()Oid

Write the tree to the given repository.

Commits

A commit is a snapshot of the working dir with meta informations like author, committer and others.

class pygit2.Commit

Commit objects.

author

The author of the commit.

commit_time

Commit time.

commit_time_offset

Commit time offset.

committer

The committer of the commit.

gpg_signature

A tuple with the GPG signature and the signed payload.

message

The commit message, a text string.

message_encoding

Message encoding.

parent_ids

The list of parent commits’ ids.

parents

The list of parent commits.

raw_message

Message (bytes).

tree

The tree object attached to the commit.

tree_id

The id of the tree attached to the commit.

Signatures

The author and committer attributes of commit objects are Signature objects:

>>> commit.author
<pygit2.Signature object at 0x7f75e9b1f5f8>

Signatures can be compared for (in)equality.

class pygit2.Signature

Signature.

email

Email address.

name

Name.

offset

Offset from UTC in minutes.

raw_email

Email (bytes).

raw_name

Name (bytes).

time

Unix time.

Creating commits

class pygit2.Repository(path=None, flags=0)
create_commit(reference_name, author, committer, message, tree, parents[, encoding])Oid

Create a new commit object, return its oid.

Commits can be created by calling the create_commit method of the repository with the following parameters:

>>> author = Signature('Alice Author', 'alice@authors.tld')
>>> committer = Signature('Cecil Committer', 'cecil@committers.tld')
>>> tree = repo.TreeBuilder().write()
>>> repo.create_commit(
... 'refs/heads/master', # the name of the reference to update
... author, committer, 'one line commit message\n\ndetailed commit message',
... tree, # binary string representing the tree object ID
... [] # list of binary strings representing parents of the new commit
... )
'#\xe4<u\xfe\xd6\x17\xa0\xe6\xa2\x8b\xb6\xdc35$\xcf-\x8b~'

Tags

A tag is a static label for a commit. See references for more information.

class pygit2.Tag

Tag objects.

get_object()object

Retrieves the object the current tag is pointing to.

message

Tag message.

name

Tag name.

raw_message

Tag message (bytes).

raw_name

Tag name (bytes).

tagger

Tagger.

target

Tagged object.

Creating tags

class pygit2.Repository(path=None, flags=0)
create_tag(name, oid, type, tagger, message)Oid

Create a new tag object, return its oid.