### Navigate to Example Directory

Source: https://pipelines.lsst.io/getting-started/uber-cal.html

Start in the top directory of the example git repository to set up your shell session.

```bash
cd $RC2_SUBSET_DIR

```

--------------------------------

### Setup Installed Dataset

Source: https://pipelines.lsst.io/modules/lsst.ap.verify/datasets-install.html

After installation, set up the dataset for the current session. Use the appropriate command based on how the dataset was installed.

```bash
setup ap_verify_ci_cosmos_pdr2              # Installed with rebuild

```

```bash
setup -r /my/path/ap_verify_ci_cosmos_pdr2  # Installed with git clone

```

--------------------------------

### Install and setup lsst_apps

Source: https://pipelines.lsst.io/install/top-level-packages.html

Use this command to install only the core frameworks and algorithmic code, which may be convenient when space is limited. Replace `<tag>` with the desired release tag.

```bash
eups distrib install lsst_apps -t <tag>
setup lsst_apps

```

--------------------------------

### Install Gaussian PSF Task Example

Source: https://pipelines.lsst.io/modules/lsst.meas.algorithms/tasks/lsst.meas.algorithms.installGaussianPsf.InstallGaussianPsfTask.html

Demonstrates how to use InstallGaussianPsfTask to set a Gaussian PSF model on an exposure. The example verifies that the measured FWHM of the created PSF is close to the configured FWHM.

```python
from lsst.afw.image import ExposureF
from lsst.meas.algorithms.installGaussianPsf import InstallGaussianPsfTask, FwhmPerSigma

exposure = ExposureF(100, 100)
task = InstallGaussianPsfTask()
task.run(exposure=exposure)

 # This particular exposure had no PSF model to begin with, so the new PSF model
 # uses the config's FWHM. However, measured FWHM is based on the truncated
 # PSF image, so it does not exactly match the input
 center = exposure.getBBox().getCenter()
 measFwhm = exposure.getPsf().computeShape(center).getDeterminantRadius() * FwhmPerSigma
 assert abs(measFwhm - task.config.fwhm) < 1e-3

```

--------------------------------

### InstallEups Example

Source: https://pipelines.lsst.io/py-api/lsst.sconsUtils.installation.SConsUtilsEnvironment.html

Installs a ups directory, setting absolute versions as appropriate. Presetup allows overriding versioning behavior.

```python
env.InstallEups(
    os.path.join(env["prefix"], "ups"),
    presetup={"sconsUtils": env["version"]},
)

```

--------------------------------

### Install ctrl_bps_htcondor Plugin

Source: https://pipelines.lsst.io/modules/lsst.ctrl.bps.htcondor/userguide.html

Clone the repository, navigate to the directory, and use the setup script and scons to install the latest features.

```bash
git clone https://github.com/lsst/ctrl_bps_htcondor
cd ctrl_bps_htcondor
setup -k -r .
scons

```

--------------------------------

### Set Up LSST Science Pipelines

Source: https://pipelines.lsst.io/install/lsstsw.html

Use the `setup` command to configure your environment with the installed LSST Science Pipelines.

```bash
setup lsst_distrib

```

--------------------------------

### List Set Up Packages

Source: https://pipelines.lsst.io/install/setup.html

Use 'eups list -s' to view currently set up packages and their versions. Run 'eups list' to see all installed packages, regardless of their setup status.

```bash
eups list -s
```

```bash
eups list
```

--------------------------------

### Install and setup lsst_distrib

Source: https://pipelines.lsst.io/install/top-level-packages.html

Use this command to install all core Science Pipelines functionality, including measurement algorithms and cluster execution middleware. Replace `<tag>` with the desired release tag.

```bash
eups distrib install lsst_distrib -t <tag>
setup lsst_distrib

```

--------------------------------

### Create and navigate to installation directory

Source: https://pipelines.lsst.io/install/lsstinstall.html

Create a directory for the LSST Science Pipelines installation and change into it.

```bash
mkdir -p lsst_stack
cd lsst_stack
```

--------------------------------

### Navigate to Example Directory

Source: https://pipelines.lsst.io/getting-started/multiband-analysis.html

Change the current directory to the top directory of the example git repository.

```bash
cd $RC2_SUBSET_DIR
```

--------------------------------

### List Setup Packages

Source: https://pipelines.lsst.io/modules/lsst.analysis.tools/getting-started.html

Check which packages are currently set up in your environment. This command is useful for verifying that analysis_tools has been correctly installed and is recognized by the stack.

```bash
eups list -s
```

--------------------------------

### Setup and Run the Demo

Source: https://pipelines.lsst.io/install/demo.html

Set up the processing package and execute the demo script. This will create a Butler data repository and process sample data.

```bash
setup -r .
./bin/run_demo.sh
```

--------------------------------

### Create and Navigate to Demo Directory

Source: https://pipelines.lsst.io/install/demo.html

Create a directory for the demo data and change into it.

```bash
mkdir -p demo_data
cd demo_data
```

--------------------------------

### Install Jupyterlab and Firefly Extension

Source: https://pipelines.lsst.io/modules/lsst.display.firefly/using-firefly-standalone.html

Installs Jupyterlab, nodejs, ipywidgets, and the Firefly Jupyterlab extension within the Science Pipelines container. This is a one-time setup step.

```bash
conda install jupyterlab nodejs ipywidgets
npm install —global babel-cli
jupyter labextension install @jupyter-widgets/jupyterlab-manager
jupyter labextension install jupyter_firefly_extensions
pip install jupyter_firefly_extensions
jupyter serverextension enable --py jupyter_firefly_extensions

```

--------------------------------

### Set up the package in EUPS

Source: https://pipelines.lsst.io/install/package-development.html

From the package's root directory, use the 'setup' command to integrate it into the EUPS stack for the current user.

```bash
setup -r . -t $USER

```

--------------------------------

### Example: runInit Configuration

Source: https://pipelines.lsst.io/modules/lsst.ctrl.bps/quickstart.html

Illustrates how to configure `runInit` to include `pipetask --init-only` and specifies the `runQuantumCommand` for initialization. Ensure that if both `--output` and `--output-run` are used in `pipetaskInit`, they are also present in other `runQuantumCommand` specifications.

```yaml
payload:
  runInit: true

pipetask:
  pipetaskInit:
    runQuantumCommand: "${CTRL_MPEXEC_DIR}/bin/pipetask --long-log run -b {butlerConfig} -i {inCollection} --output {output} --output-run {outputRun} --init-only --register-dataset-types --qgraph {qgraphFile} --clobber-outputs"
    requestMemory: 2048

```

--------------------------------

### Set Up Top-Level Package

Source: https://pipelines.lsst.io/install/setup.html

After loading the environment, set up a top-level package like 'lsst_apps' or 'lsst_distrib' to make its functionality available.

```bash
setup <package>
```

```bash
setup lsst_apps
```

```bash
setup lsst_distrib
```

--------------------------------

### getEnvironmentPackages

Source: https://pipelines.lsst.io/py-api/lsst.utils.packages.getEnvironmentPackages.html

Retrieves a dictionary of installed products and their versions from the environment. It can optionally include all setup packages, not just locally-setup ones.

```APIDOC
## getEnvironmentPackages

### Description
Get products and their versions from the environment.

### Method
`getEnvironmentPackages(_include_all : bool = False_)`

### Parameters
#### Query Parameters
- **include_all** (bool) - Optional - If `False` only returns locally-setup packages. If `True` all set up packages are returned with a version that includes any associated non-current tags.

### Returns
- **packages** (dict[str, str]) - A dictionary where keys are product names (str) and values are their versions (str).

### Notes
Uses EUPS to determine versions for certain products and to check for uninstalled packages. Only reports product/version for these unless `include_all` is `True`. Assumes no new EUPS packages are set up after the first call.
```

--------------------------------

### Example Subclass for ObsTests

Source: https://pipelines.lsst.io/py-api/lsst.obs.base.tests.ObsTests.html

Demonstrates how to create a subclass that inherits from lsst.obs.base.tests.ObsTests and lsst.utils.tests.TestCase, including necessary setup calls.

```python
class TestObs(
    lsst.obs.base.tests.ObsTests, lsst.utils.tests.TestCase
):
    def setUp(self):
        self.setUp_tests(...)
        self.setUp_butler_get(...)
        self.setUp_camera(...)

```

--------------------------------

### Graph Degree Examples

Source: https://pipelines.lsst.io/py-api/lsst.ctrl.bps.htcondor.HTCDag.html

Demonstrates how to get the degree of nodes in a directed graph. Use this to find the number of edges connected to a node.

```python
>>> G = nx.DiGraph()  # or MultiDiGraph
>>> nx.add_path(G, [0, 1, 2, 3])
>>> G.degree(0)  # node 0 with degree 1
1
>>> list(G.degree([0, 1, 2]))
[(0, 1), (1, 2), (2, 2)]
```

--------------------------------

### Get Full Task Name

Source: https://pipelines.lsst.io/py-api/lsst.ip.isr.IsrTask.html

Obtains the hierarchical name of the task, including parent task names, separated by periods. For example, 'top.sub.sub2'.

```python
fullName = task.getFullName()
```

--------------------------------

### Example: Creating and Updating a DemoConfig

Source: https://pipelines.lsst.io/py-api/lsst.cp.pipe.PlotPhotonTransferCurveConfig.html

Demonstrates how to define a Config subclass with fields, instantiate it, and update its values using the update method.

```python
>>> from lsst.pex.config import Config, Field
>>> class DemoConfig(Config):
...     fieldA = Field(doc="Field A", dtype=int, default=42)
...     fieldB = Field(doc="Field B", dtype=bool, default=True)
...     fieldC = Field(doc="Field C", dtype=str, default="Hello world")
>>> config = DemoConfig()


```

```python
>>> for name, value in config.iteritems():
...     print(f"{name}: {value}")
fieldA: 42
fieldB: True
fieldC: 'Hello world'


```

```python
>>> config.update(fieldA=13, fieldC="Updated!")


```

```python
>>> for name, value in config.iteritems():
...     print(f"{name}: {value}")
fieldA: 13
fieldB: True
fieldC: 'Updated!'

```

--------------------------------

### Get Full Metadata Example

Source: https://pipelines.lsst.io/py-api/lsst.pipe.tasks.postprocess.TransformCatalogBaseTask.html

Retrieves metadata for all tasks, including timing information and task-specific metadata. Metadata keys are hierarchical task names.

```python
metadata = task.getFullMetadata()
# metadata is a TaskMetadata object
# The keys are the full task name, e.g.:
# 'topLevelTaskName:subtaskName:subsubtaskName.itemName'
```

--------------------------------

### Build Science Pipelines Packages

Source: https://pipelines.lsst.io/install/lsstsw.html

Use the `rebuild` command to build the `lsst_distrib` package. The `-t current` argument tags the installed packages for automatic setup.

```bash
rebuild -t current lsst_distrib

```

--------------------------------

### List all set up packages

Source: https://pipelines.lsst.io/install/package-development.html

Display all packages currently set up in the EUPS environment, including development packages.

```bash
eups list -s

```

--------------------------------

### DemoConfig Example: Initialization and Iteration

Source: https://pipelines.lsst.io/py-api/lsst.analysis.ap.PlotImageSubtractionCutoutsConfig.html

Demonstrates the creation of a custom Config class with fields and iterating over its default values.

```python
>>> from lsst.pex.config import Config, Field
>>> class DemoConfig(Config):
...     fieldA = Field(doc="Field A", dtype=int, default=42)
...     fieldB = Field(doc="Field B", dtype=bool, default=True)
...     fieldC = Field(doc="Field C", dtype=str, default="Hello world")
>>> config = DemoConfig()
```

```python
>>> for name, value in config.iteritems():
...     print(f"{name}: {value}")
fieldA: 42
fieldB: True
fieldC: 'Hello world'
```

--------------------------------

### Verify LSST Science Pipelines Installation

Source: https://pipelines.lsst.io/getting-started/data-setup.html

Run this command in your shell to confirm that the LSST Science Pipelines environment is correctly set up. Look for the word 'setup' in the output.

```bash
eups list lsst_distrib

```

--------------------------------

### Defining and Using a Demo Configuration

Source: https://pipelines.lsst.io/py-api/lsst.meas.extensions.shapeHSM.HsmPsfMomentsConfig.html

Demonstrates how to define a custom configuration class with fields and their default values. This example shows how to instantiate the config and iterate over its fields.

```python
from lsst.pex.config import Config, Field
class DemoConfig(Config):
    fieldA = Field(doc="Field A", dtype=int, default=42)
    fieldB = Field(doc="Field B", dtype=bool, default=True)
    fieldC = Field(doc="Field C", dtype=str, default="Hello world")
config = DemoConfig()
```

```python
for name, value in config.iteritems():
    print(f"{name}: {value}")
```

```python
for name, value in config.iteritems():
    print(f"{name}: {value}")
```

--------------------------------

### Import and Initialize Debug Info

Source: https://pipelines.lsst.io/py-api/lsstDebug.Info.html

Import the lsstDebug module and create an Info object for the current module. This example shows how to get the 'display' debug flag, which will initially be False.

```python
import lsstDebug

display = lsstDebug.Info(__name__).display
```

--------------------------------

### Define a Scalar Action

Source: https://pipelines.lsst.io/modules/lsst.analysis.tools/getting-started.html

Example of a scalar action that calculates the median of a vector. It defines a configuration option for the vector key and implements methods to get the input schema and perform the calculation.

```python
class MedianAction(ScalarAction):
    vectorKey = Field[str]("Key of Vector to median.")

    def getInputSchema(self) -> KeyedDataSchema:
        return ((self.vectorKey, Vector),)

    def __call__(self, data: KeyedData, **kwargs) -> Scalar:
        mask = self.getMask(**kwargs)
        return cast(Scalar, float(np.nanmedian(cast(Vector, data[self.vectorKey.format(**kwargs)])[mask])))

```

--------------------------------

### Python Plugin Class Setup for Logging

Source: https://pipelines.lsst.io/modules/lsst.meas.base/tasks_and_algorithms.html

Example of a Python plugin class configured for internal logging. It requires the hasLogName class attribute to be True and the constructor to accept a logName parameter.

```python
class SingleFrameTestPlugin(SingleFramePlugin):

    ConfigClass = SingleFrameTestConfig
    hasLogName = True

    def __init__(self, config, name, schema, metadata, logName=None):
        SingleFramePlugin.__init__(self, config, name, schema, metadata, logName=logName)
```

--------------------------------

### Configuration Parameter History Examples

Source: https://pipelines.lsst.io/modules/lsst.ctrl.mpexec/configuring-pipetask-tasks.html

These examples show the output of querying configuration parameter history, illustrating different values and their origins.

```text
[]                                               $CTRL_MPEXEC_DIR/bin/pipetask:29                                                     sys.exit(main())
                                                ctrl/mpexec/cli/pipetask.py:51
                                                daf/butler/cli/utils.py:1069
                                                ctrl/mpexec/cli/cmd/commands.py:106
                                                ctrl/mpexec/cli/script/build.py:89
                                                ctrl/mpexec/showInfo.py:138
                                                ctrl/mpexec/showInfo.py:226
                                                ctrl/mpexec/util.py:143
                                                pipe/base/pipeline.py:668
                                                pipe/base/pipeline.py:691
                                                pex/config/configurableField.py:421
                                                pex/config/configurableField.py:421
                                                ip/isr/assembleCcdTask.py:39
```

```text
[]                                               $CTRL_MPEXEC_DIR/bin/pipetask:29                                                     sys.exit(main())
                                                ctrl/mpexec/cli/pipetask.py:51
                                                daf/butler/cli/utils.py:1069
                                                ctrl/mpexec/cli/cmd/commands.py:106
                                                ctrl/mpexec/cli/script/build.py:89
                                                ctrl/mpexec/showInfo.py:138
                                                ctrl/mpexec/showInfo.py:226
                                                ctrl/mpexec/util.py:143
                                                pipe/base/pipeline.py:668
                                                pipe/base/pipeline.py:691
                                                pex/config/configurableField.py:421
                                                pex/config/configurableField.py:421
```

```text
['PC001001', 'PC001002', 'PC002001', 'PC002002'] $CTRL_MPEXEC_DIR/bin/pipetask:29                                                     sys.exit(main())
                                                ctrl/mpexec/cli/pipetask.py:51
                                                daf/butler/cli/utils.py:1069
                                                ctrl/mpexec/cli/cmd/commands.py:106
                                                ctrl/mpexec/cli/script/build.py:89
                                                ctrl/mpexec/showInfo.py:138
                                                ctrl/mpexec/showInfo.py:226
                                                ctrl/mpexec/util.py:143
                                                pipe/base/pipeline.py:668
                                                pipe/base/pipeline.py:711
                                                pipe/base/configOverrides.py:299
                                                pipe/base/_instrument.py:298
                                                pex/config/config.py:1167
                                                pex/config/config.py:1251
                                                $EUPS_PATH/Darwin/obs_subaru/g56afc215e3+576f275b99/config/isr.py:33    config.assembleCcd.keysToRemove = ["PC001001", "PC001002", "PC002001", "PC002002"]
```

```text
['A', 'B']                                       $CTRL_MPEXEC_DIR/bin/pipetask:29                                                     sys.exit(main())
                                                ctrl/mpexec/cli/pipetask.py:51
                                                daf/butler/cli/utils.py:1069
                                                ctrl/mpexec/cli/cmd/commands.py:106
                                                ctrl/mpexec/cli/script/build.py:89
                                                ctrl/mpexec/showInfo.py:138
                                                ctrl/mpexec/showInfo.py:226
                                                ctrl/mpexec/util.py:143
                                                pipe/base/pipeline.py:668
                                                pipe/base/pipeline.py:711
                                                pipe/base/configOverrides.py:285
```

--------------------------------

### DemoConfig Example

Source: https://pipelines.lsst.io/py-api/lsst.analysis.tools.actions.plot.HistPanel.html

Demonstrates the creation and default values of a custom Config class. Shows how to iterate over config fields and their values.

```python
from lsst.pex.config import Config, Field
class DemoConfig(Config):
    fieldA = Field(doc="Field A", dtype=int, default=42)
    fieldB = Field(doc="Field B", dtype=bool, default=True)
    fieldC = Field(doc="Field C", dtype=str, default="Hello world")
config = DemoConfig()
```

```python
for name, value in config.iteritems():
    print(f"{name}: {value}")
```

--------------------------------

### lsst.display.ds9.get()

Source: https://pipelines.lsst.io/py-api/lsst.display.ds9.get.html

The `get()` function is used to retrieve information from the DS9 display. It takes several arguments to specify what information to get and how to get it.

```APIDOC
## lsst.display.ds9.get()

### Description
Retrieves information from the DS9 display.

### Signature
`get(_xpa : lsst.display.ds9.xpa.xparec_, _xtemplate : str_, _paramList : str_, _mode : str_) -> str`

### Parameters
* `_xpa` (lsst.display.ds9.xpa.xparec_) - The XPA connection object.
* `_xtemplate` (str) - The template string for the command.
* `_paramList` (str) - A comma-separated list of parameters to retrieve.
* `_mode` (str) - The mode of operation (e.g., 'sync', 'async').

### Returns
* `str` - The retrieved information as a string.
```

--------------------------------

### DemoConfig Example

Source: https://pipelines.lsst.io/py-api/lsst.ip.isr.OverscanAmpConfig.html

Demonstrates the creation and usage of a custom Config class with fields, showing default values and updates.

```python
from lsst.pex.config import Config, Field
class DemoConfig(Config):
    fieldA = Field(doc="Field A", dtype=int, default=42)
    fieldB = Field(doc="Field B", dtype=bool, default=True)
    fieldC = Field(doc="Field C", dtype=str, default="Hello world")
```

```python
config = DemoConfig()

for name, value in config.iteritems():
    print(f"{name}: {value}")
```

```python
config.update(fieldA=13, fieldC="Updated!")

for name, value in config.iteritems():
    print(f"{name}: {value}")
```

--------------------------------

### get

Source: https://pipelines.lsst.io/py-api/lsst.sconsUtils.installation.SConsUtilsEnvironment.html

Emulates dictionary get() method.

```APIDOC
## get

### Description
Emulates the get() method of dictionaries.

### Method
get

### Parameters
* `key`: The key to retrieve.
* `default`: The default value to return if the key is not found (optional).
```

--------------------------------

### ExampleTask __init__ Method

Source: https://pipelines.lsst.io/modules/lsst.pipe.base/creating-a-task.html

Constructs an ExampleTask by calling the parent constructor and making a 'stats' subtask from a configuration field.

```python
def __init__(self, *args, **kwargs):
    """Construct an ExampleTask

    Call the parent class constructor and make the "stats" subtask from the config field of the same name.
    """
    super().__init__(self, *args, **kwargs)
    self.makeSubtask("stats")

```

--------------------------------

### Set Up Local Faro Package

Source: https://pipelines.lsst.io/modules/lsst.faro/using.html

Navigates into the cloned faro directory and sets up the local version of the package for development.

```bash
cd faro
setup -k -r .
```

--------------------------------

### Install Dataset with rebuild

Source: https://pipelines.lsst.io/modules/lsst.ap.verify/datasets-install.html

Use the LSST Software Build Tool to install a specific dataset package. This is the recommended method for installing datasets.

```bash
rebuild -u ap_verify_ci_cosmos_pdr2

```

--------------------------------

### Define and Initialize a DemoConfig

Source: https://pipelines.lsst.io/py-api/lsst.afw.cameraGeom.CameraConfig.html

Demonstrates how to define a simple configuration class with fields and initialize an instance with default values.

```python
from lsst.pex.config import Config, Field
class DemoConfig(Config):
    fieldA = Field(doc="Field A", dtype=int, default=42)
    fieldB = Field(doc="Field B", dtype=bool, default=True)
    fieldC = Field(doc="Field C", dtype=str, default="Hello world")
config = DemoConfig()
```

--------------------------------

### SerializedDimensionRecord Configuration Example

Source: https://pipelines.lsst.io/py-api/lsst.daf.butler.SerializedDimensionRecord.html

This example shows the configuration for the SerializedDimensionRecord model, including an example of its expected JSON schema structure for 'definition' and 'record' fields.

```python
model_config: ClassVar[ConfigDict]__ = {'json_schema_extra': {'examples': [{'definition': 'detector', 'record': {'instrument': 'HSC', 'id': 72, 'full_name': '0_01', 'name_in_raft': '01', 'raft': '0', 'purpose': 'SCIENCE'}}]}}
```

--------------------------------

### Install LSST Science Pipelines Release

Source: https://pipelines.lsst.io/install/lsstinstall.html

Installs the specified release of the `lsst_distrib` package using EUPS. Ensure the release tag matches your installation needs.

```bash
eups distrib install -t v29_2_1 lsst_distrib
curl -sSL https://raw.githubusercontent.com/lsst/shebangtron/main/shebangtron | python
setup lsst_distrib

```

--------------------------------

### Setup Sample Data Package

Source: https://pipelines.lsst.io/getting-started/data-setup.html

Set up the cloned rc2_subset package to add it to the EUPS stack. The -j flag ensures only this package is set up.

```bash
setup -j -r rc2_subset
```

--------------------------------

### Instantiate and Use Packages Object

Source: https://pipelines.lsst.io/py-api/lsst.utils.packages.Packages.html

Demonstrates how to create a Packages object from the system, read from a file, and compare package sets. Useful for tracking dependencies and changes.

```python
from lsst.utils.packages import Packages
pkgs = Packages.fromSystem()
print("Current packages:", pkgs)
old = Packages.read("/path/to/packages.pickle")
print("Old packages:", old)
print("Missing packages compared to before:", pkgs.missing(old))
print("Extra packages compared to before:", pkgs.extra(old))
print("Different packages: ", pkgs.difference(old))
old.update(pkgs)  # Include any new packages in the old
old.write("/path/to/packages.pickle")
```

--------------------------------

### get

Source: https://pipelines.lsst.io/py-api/lsst.sconsUtils.installation.SConsUtilsEnvironment.html

Emulates the dictionary get() method to retrieve an environment variable.

```APIDOC
## get

### Parameters
* **key** (str): The key of the environment variable to retrieve.
* **default**: The default value to return if the key is not found (defaults to None).

### Returns
The value of the environment variable or the default value.
```

--------------------------------

### DemoConfig Example

Source: https://pipelines.lsst.io/py-api/lsst.analysis.tools.actions.keyedData.AddComputedVector.html

Demonstrates creating a Config subclass, accessing default values, and updating specific fields using the 'update' method.

```python
>>> from lsst.pex.config import Config, Field
>>> class DemoConfig(Config):
...     fieldA = Field(doc="Field A", dtype=int, default=42)
...     fieldB = Field(doc="Field B", dtype=bool, default=True)
...     fieldC = Field(doc="Field C", dtype=str, default="Hello world")
>>> config = DemoConfig()
```

```python
>>> for name, value in config.iteritems():
...     print(f"{name}: {value}")
fieldA: 42
fieldB: True
fieldC: 'Hello world'
```

```python
>>> config.update(fieldA=13, fieldC="Updated!")
```

--------------------------------

### Example Usage

Source: https://pipelines.lsst.io/modules/lsst.meas.algorithms/tasks/lsst.meas.algorithms.readFitsCatalogTask.ReadFitsCatalogTask.html

Example of how to use the ReadFitsCatalogTask to read a FITS catalog.

```APIDOC
from lsst.meas.algorithms.readFitsCatalogTask import ReadFitsCatalogTask
filePath = "tests/data/testReadFitsCatalog.fits"
task = ReadFitsCatalogTask()
catalogArray = task.run(filePath)
```

--------------------------------

### Run SourceDetectionTask Example

Source: https://pipelines.lsst.io/modules/lsst.meas.algorithms/tasks/lsst.meas.algorithms.SourceDetectionTask.html

Command to run the example script for SourceDetectionTask.

```bash
examples/measAlgTasks.py --doDisplay

```

--------------------------------

### DemoConfig Example

Source: https://pipelines.lsst.io/py-api/lsst.analysis.tools.tasks.SourceObjectTableAnalysisConfig.html

Demonstrates creating a `DemoConfig` with fields, accessing default values using `iteritems`, updating fields using the `update` method, and then re-accessing the updated values.

```python
from lsst.pex.config import Config, Field
class DemoConfig(Config):
    fieldA = Field(doc="Field A", dtype=int, default=42)
    fieldB = Field(doc="Field B", dtype=bool, default=True)
    fieldC = Field(doc="Field C", dtype=str, default="Hello world")
config = DemoConfig()
```

```python
for name, value in config.iteritems():
    print(f"{name}: {value}")
```

```python
config.update(fieldA=13, fieldC="Updated!")
```

```python
for name, value in config.iteritems():
    print(f"{name}: {value}")
```

--------------------------------

### Setup and Build analysis_tools

Source: https://pipelines.lsst.io/modules/lsst.analysis.tools/getting-started.html

Set up the cloned analysis_tools package and build it using scons. The -j flag can be used to parallelize the build process.

```bash
setup -j -r repos/analyis_tools
```

```bash
scons repos/analysis_tools
```

--------------------------------

### InstallEups

Source: https://pipelines.lsst.io/py-api/lsst.sconsUtils.installation.SConsUtilsEnvironment.html

Installs a UPS directory, setting absolute versions as appropriate, unless installing from the trunk.

```APIDOC
## InstallEups

### Description
Install a ups directory, setting absolute versions as appropriate (unless you’re installing from the trunk, in which case no versions are expanded).

### Method
InstallEups

### Parameters
#### Path Parameters
- **dest** (str) - Required - Destination directory.
- **files** (collections.abc.Sequence) - Optional - List of files to install. Any build/table files present in './ups' are automatically added to this list.
- **presetup** (dict) - Optional - A dictionary with keys product names and values the version that should be installed into the table files, overriding eups expandtable’s usual behaviour.

### Returns
- **list** - Commands to execute.

### Notes
Sample usage:
```
env.InstallEups(
    os.path.join(env["prefix"], "ups"),
    presetup={"sconsUtils": env["version"]},
)

```
```