commit

Record changes to files or directories tracked by DVC.

Synopsis

usage: dvc commit [-h] [-q | -v] [-f] [-d] [-R]
                  [targets [targets ...]]

positional arguments:
  targets        Limit command scope to these stages or .dvc files.
                 Using -R, directories to search for stages or .dvc
                 files can also be given.

Description

Stores the current contents of files and directories tracked by DVC in the cache, and updates dvc.lock or .dvc files if/as needed. This forces DVC to accept any changed contents of tracked data currently in the workspace. We explore the scenarios in which this can be useful next.

💡 For convenience, a pre-commit Git hook is available to remind you to dvc commit when needed. See dvc install for more info.

dvc commit provides a way to complete DVC commands that track data (dvc add, dvc repro, dvc import, etc.), when they have been used with the --no-commit or --no-exec options. Those options cause the command to skip these step(s) during the process of tracking each file or directory:

• Save the hash value of the file/dir in the dvc.lock or .dvc file.
• Store the file contents in the cache.

Skipping these steps is typically done to avoid caching unfinished data, for example when exploring different data or stages).

More specifically, scenarios for dvc commit include:

• As an alternative to dvc add for data that's already tracked. For example, you can "dvc add" all the changed files or directories already tracked by DVC without having to name each target.
• Often we edit source code, configuration, or other files that are specified as dependencies in dvc.yaml (deps field) in a way that doesn't cause any changes to stage outputs. For example: reformatting input data, adding code comments, etc. However, DVC notices all changes to dependencies and expects you to reproduce the corresponding pipeline (dvc repro). You can use dvc commit instead to force accepting these new versions without having to execute stage commands.
• Sometimes after executing a stage, we realize that not all of its dependencies or outputs are defined in dvc.yaml. It is possible to add the missing deps/outs without having to re-execute stages, and dvc commit is needed to finalize the operation (see link).

• It's also possible to execute stage commands by hand (without dvc repro), or to manually modify their output files or directories. Use dvc commit to register the changes with DVC once you're done.

  Note that dvc unprotect (or removing the outputs) is usually required before rewriting files/dirs tracked by DVC.

Note that it's best to try avoiding these scenarios, where the cache, dvc.lock, and .dvc files are force-updated. DVC can't guarantee reproducibility in those cases.

Options

• -d, --with-deps - determines files to commit by tracking dependencies to the target stages or .dvc files. If no targets are provided, this option is ignored. By traversing all stage dependencies, DVC searches backward from the target stages in the corresponding pipelines. This means DVC will not commit files referenced in later stages than the targets.
• -R, --recursive - determines the files to commit by searching each target directory and its subdirectories for stages or .dvc files to inspect. If there are no directories among the targets, this option is ignored.
• -f, --force - commit data even if hash values for dependencies or outputs did not change.
• -h, --help - prints the usage/help message, and exit.
• -q, --quiet - do not write anything to standard output. Exit with 0 if no problems arise, otherwise 1.
• -v, --verbose - displays detailed tracing information from executing the dvc add command.

Examples

Let's employ a simple workspace with some data, code, ML models, pipeline stages, such as the DVC project created for the Get Started. Then we can see what happens with git commit and dvc commit in different situations.

$ git clone https://github.com/iterative/example-get-started
$ cd example-get-started

$ python3 -m venv .env
$ source .env/bin/activate
$ pip install -r src/requirements.txt

$ dvc pull -aT

Example: Rapid iterations

Sometimes we want to iterate through multiple changes to configuration, code, or data, trying different ways to improve the output of a stage. To avoid filling the cache with undesired intermediate results, we can run a single stage with dvc run --no-commit, or reproduce an entire pipeline using dvc repro --no-commit. This prevents data from being pushed to cache. When development of the stage is finished, dvc commit can be used to store data files in the cache.

In the featurize stage, src/featurization.py is executed. A useful change to make is adjusting the parameters for that script. The parameters are defined in the params.yaml file. Updating the value of the max_features param to 6000 changes the resulting model:

featurize:
  max_features: 6000
  ngrams: 2

This edit introduces a change that would cause the featurize, train and evaluate stages to execute if we ran dvc repro. But if we want to try several values for max_features and save only the best result to the cache, we can run it like this:

$ dvc repro --no-commit

We can run this command as many times as we like, editing params.yaml any way we like, and so long as we use --no-commit, the data does not get saved to the cache. Let's verify that's the case:

First verification:

$ dvc status
featurize:
	changed outs:
		not in cache:       data/features
train:
	changed outs:
		not in cache:       model.pkl

Now we can look in the cache directory to see if the new version of model.pkl is not in cache indeed. Let's look at the latest state of train in dvc.lock first:

train:
  cmd: python src/train.py data/features model.pkl
  deps:
    - path: data/features
      md5: de03a7e34e003e54dde0d40582c6acf4.dir
    - path: src/train.py
      md5: ad8e71b2cca4334a7d3bb6495645068c
  params:
    params.yaml:
      train.n_estimators: 100
      train.seed: 20170428
  outs:
    - path: model.pkl
      md5: 9aba000ba83b341a423a81eed8ff9238

To verify this instance of model.pkl is not in the cache, we must know the path to the cached file. In the cache directory, the first two characters of the hash value are used as a subdirectory name, and the remaining characters are the file name. Therefore, had the file been committed to the cache, it would appear in the directory .dvc/cache/9a. Let's check:

$ ls .dvc/cache/9a
ls: .dvc/cache/9a: No such file or directory

If we've determined the changes to params.yaml were successful, we can execute this set of commands:

$ dvc commit
$ dvc status
Data and pipelines are up to date.
$ ls .dvc/cache/70
ba000ba83b341a423a81eed8ff9238

We've verified that dvc commit has saved the changes into the cache, and that the new instance of model.pkl is there.

Example: Executing stage commands without DVC

Sometimes you may want to execute stage commands manually (instead of using dvc repro). You won't have DVC helping you, but you'll have the freedom to run any command, even ones not defined in dvc.yaml. For example:

$ python src/featurization.py data/prepared data/features
$ python src/train.py data/features model.pkl
$ python src/evaluate.py model.pkl data/features auc.metric

As before, dvc status will show which tracked files/dirs have changed, and when your work is finalized, dvc commit will save the outputs the cache.

Example: Updating dependencies

Sometimes we want to clean up a code or configuration file in a way that doesn't cause a change in its results. We might write in-line documentation with comments, change indentation, remove some debugging printouts, or any other change that doesn't produce different output of pipeline stages.

$ git status -s
M src/train.py

$ dvc status
train:
	changed deps:
		modified:           src/train.py

Let's edit one of the source code files. It doesn't matter which one. You'll see that both Git and DVC recognize a change was made.

If we ran dvc repro at this point, this pipeline would be reproduced. But since the change was inconsequential, that would be a waste of time and CPU. That's especially critical if the corresponding stages take lots of resources to execute.

$ git add src/train.py

$ git commit -m "CHANGED"
[master 72327bd] CHANGED
1 file changed, 2 insertions(+)

$ dvc commit
dependencies ['src/train.py'] of 'train.dvc' changed.
Are you sure you commit it? [y/n] y

$ dvc status
Data and pipelines are up to date.

Instead of reproducing the pipeline for changes that do not produce different results, just use commit on both Git and DVC.