# Editing a Package

Data in Quilt is organized in terms of **data packages**. A data package is a logical group of files, directories, and metadata.

### Initializing a package

To edit a new empty package, use the package constructor:

```python
import quilt3
p = quilt3.Package()
```

To edit a preexisting package, we need to first make sure to install the package:

```python
quilt3.Package.install(
    "examples/hurdat",
    "s3://quilt-example",
)
```

```
Loading manifest: 100%|██████████| 5/5 [00:00<00:00, 5902.48entries/s]

Successfully installed package 'examples/hurdat', tophash=f8d1478 from s3://quilt-example

```

Use `browse` to edit the package:

```python
p = quilt3.Package.browse('examples/hurdat')
```

```
Loading manifest: 100%|██████████| 5/5 [00:00<00:00, 9920.30entries/s]
```

For more information on accessing existing packages see the section "[Installing a Package](/version-3.2.1/walkthrough/installing-a-package.md)".

### Adding data to a package

Use the `set` and `set_dir` commands to add individual files and whole directories, respectively, to a `Package`:

```python
# add entries individually using `set`
# ie p.set("foo.csv", "/local/path/foo.csv"),
# p.set("bar.csv", "s3://bucket/path/bar.csv")

# create test data
with open("data.csv", "w") as f:
    f.write("id, value\na, 42")

p = quilt3.Package()
p.set("data.csv", "data.csv")
p.set("banner.png", "s3://quilt-example/imgs/banner.png")

# or grab everything in a directory at once using `set_dir`
# ie p.set_dir("stuff/", "/path/to/stuff/"),
# p.set_dir("things/", "s3://path/to/things/")

# create test directory
import os
os.mkdir("data")
p.set_dir("stuff/", "./data/")
p.set_dir("imgs/", "s3://quilt-example/imgs/")
```

```
(remote Package)
 └─banner.png
 └─data.csv
 └─imgs/
   └─banner.png
 └─stuff/
```

The first parameter to these functions is the *logical key*, which will determine where the file lives within the package. So after running the commands above our package will look like this:

```python
p
```

```
(remote Package)
 └─banner.png
 └─data.csv
 └─imgs/
   └─banner.png
 └─stuff/
```

The second parameter is the *physical key*, which states the file's actual location. The physical key may point to either a local file or a remote object (with an `s3://` path).

If the physical key and the logical key are the same, you may omit the second argument:

```python
# assuming data.csv is in the current directory
p = quilt3.Package()
p.set("data.csv")
```

```
(local Package)
 └─data.csv
```

Another useful trick. Use `"."` to set the contents of the package to that of the current directory:

```python
# switch to a test directory and create some test files
import os
%cd data/
os.mkdir("stuff")
with open("new_data.csv", "w") as f:
    f.write("id, value\na, 42")

# set the contents of the package to that of the current directory
p.set_dir(".", ".")
```

```
(local Package)
 └─data.csv
 └─new_data.csv
```

### Deleting data in a package

Use `delete` to remove entries from a package:

```python
p.delete("data.csv")
```

```
(local Package)
 └─new_data.csv
```

Note that this will only remove this piece of data from the package. It will not delete the actual data itself.

### Adding metadata to a package

Packages support metadata anywhere in the package. To set metadata on package entries or directories, use the `meta` argument:

```python
p = quilt3.Package()
p.set("data.csv", "new_data.csv", meta={"type": "csv"})
p.set_dir("stuff/", "stuff/", meta={"origin": "unknown"})
```

```
(local Package)
 └─data.csv
 └─stuff/
```

You can also set metadata on the package as a whole using `set_meta`.

```python
# set metadata on a package
p.set_meta({"package-type": "demo"})
```

```
(local Package)
 └─data.csv
 └─stuff/
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.quilt.bio/version-3.2.1/walkthrough/editing-a-package.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.