Add type annotations (#44)

Fixes #36

.github/workflows/python-app.yml

@@ -56,6 +56,9 @@ jobs:
           poetry run flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
           # exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
           poetry run flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
+      - name: Check types with mypy
+        run: |
+          poetry run mypy cmr tests
       - name: Test with pytest
         run: |
           poetry run pytest

CHANGELOG.md

@@ -14,6 +14,10 @@ adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
   accommodation for Python versions older than 3.8 and updated CI build to test
   against Python versions 3.8 through 3.12.  Also, fixed all flake8 warnings.
 
+### Added
+
+- [issues/36](https://github.com/nasa/python_cmr/issues/36) Added type annotations.
+
 ## Fixed
 
 - [issues/42](https://github.com/nasa/python_cmr/issues/42) Fixed bug where a

README.md

@@ -13,13 +13,15 @@ Python CMR
 [![Python versions](https://img.shields.io/pypi/pyversions/python_cmr.svg)](https://pypi.python.org/pypi/python_cmr)
 [![Build Status](https://github.com/nasa/python_cmr/actions/workflows/python-app.yml/badge.svg)](https://github.com/nasa/python_cmr/actions)
 [![CodeQL](https://github.com/nasa/python_cmr/actions/workflows/codeql-analysis.yml/badge.svg)](https://github.com/nasa/python_cmr/actions/workflows/codeql-analysis.yml)
+[![Checked with mypy](https://www.mypy-lang.org/static/mypy_badge.svg)](https://mypy-lang.org/)
 
 Python CMR is an easy to use wrapper to the NASA
 EOSDIS [Common Metadata Repository API](https://cmr.earthdata.nasa.gov/search/). This package aims to make querying the
 API intuitive and less error-prone by providing methods that will preemptively check for invalid input and handle the
 URL encoding the CMR API expects.
 
 Getting access to NASA's earth science metadata is as simple as this:
+
 ```python
 from cmr import CollectionQuery, GranuleQuery, ToolQuery, ServiceQuery, VariableQuery
 
@@ -53,15 +55,17 @@ Installation
 ============
 
 To install from pypi:
-```
-$ pip install python-cmr
-```
 
-To install from github, perhaps to try out the dev branch:
+```plain
+pip install python-cmr
 ```
-$ git clone https://github.com/nasa/python_cmr
-$ cd python-cmr
-$ pip install .
+
+To install from GitHub, perhaps to try out the dev branch:
+
+```plain
+git clone https://github.com/nasa/python_cmr
+cd python-cmr
+pip install .
 ```
 
 Examples
@@ -72,6 +76,7 @@ methods used to build a query for CMR. Not all parameters provided by the CMR AP
 python-cmr.
 
 The following methods are available to both collection and granule queries:
+
 ```python
 # search for granules matching a specific product/short_name
 api.short_name("AST_L1T")
@@ -120,6 +125,7 @@ api.mode(CMR_UAT)
 ```
 
 Granule searches support these methods (in addition to the shared methods above):
+
 ```python
 # search for a granule by its unique ID
 api.granule_ur("SC:AST_L1T.003:2150315169")
@@ -138,12 +144,13 @@ api.cloud_cover(25, 75)
 api.instrument("MODIS")
 api.platform("Terra")
 
-# filter by a sort_key note: sort_keys are require some other fields to find some existing granules before they can be sorted
-
+# filter by a sort_key note: sort_keys are require some other fields to find
+# some existing granules before they can be sorted
 api.parameters(short_name="OMNO2", version="003", provider='GES_DISC', sort_key='-start_date')
 ```
 
 Collection searches support these methods (in addition to the shared methods above):
+
 ```python
 # search for collections from a specific archive center
 api.archive_center("LP DAAC")
@@ -162,6 +169,7 @@ api.service_concept_id('S1962070864-POCLOUD')
 ```
 
 Service searches support the following methods
+
 ```python
 # Search via provider
 api = ServiceQuery()
@@ -178,6 +186,7 @@ api.concept_id('S1962070864-POCLOUD')
 ```
 
 Tool searches support the following methods
+
 ```python
 # Search via provider
 api = ToolQuery()
@@ -194,6 +203,7 @@ api.concept_id('TL2092786348-POCLOUD')
 ```
 
 Variable searches support the following methods
+
 ```python
 # Search via provider
 api = VariableQuery()
@@ -211,6 +221,7 @@ api.concept_id('V2112019824-POCLOUD')
 
 As an alternative to chaining methods together to set the parameters of your query, a method exists to allow you to pass
 your parameters as keyword arguments:
+
 ```python
 # search for AST_L1T version 003 granules at latitude 42, longitude -100
 api.parameters(
@@ -224,6 +235,7 @@ Note: the kwarg key should match the name of a method from the above examples, a
 parameter that requires multiple values.
 
 To inspect and retrieve results from the API, the following methods are available:
+
 ```python
 # inspect the number of results the query will return without downloading the results
 print(api.hits())
@@ -240,11 +252,13 @@ granules = api.get_all()  # this is a shortcut for api.get(api.hits())
 
 By default the responses will return as json and be accessible as a list of python dictionaries. Other formats can be
 specified before making the request:
+
 ```python
 granules = api.format("echo10").get(100)
 ```
 
 We can add token to the api calls by setting headers using the following functions:
+
 ```python
 # Use token function for EDL echo-token or launchpad token
 api.token(token)
@@ -270,55 +284,66 @@ Collection queries also support the following formats:
 - dif
 - dif10
 - opendata
-- umm\_json
-- umm\_json\_vX\_Y (ex: umm\_json\_v1\_9)
+- umm_json
+- umm_json_vX_Y (ex: umm_json_v1_9)
 
-# Developing
+Developing
+==========
 
 python-cmr uses the [poetry](https://python-poetry.org/) build system. Download and install poetry before starting
 development
 
-## Install Dependencies
+Install Dependencies
+--------------------
 
 With dev dependencies:
+
 ```shell
 poetry install
 ```
 
 Without dev dependencies:
+
 ```shell
 poetry install --no-dev
 ```
 
-## Update Dependencies
+Update Dependencies
+-------------------
 
 ```shell
 poetry update
 ```
 
-## Add new Dependency
+Add new Dependency
+------------------
 
 ```shell
 poetry add requests
 ```
+
 Development-only dependency:
+
 ```shell
 poetry add --dev pytest
 ```
 
-## Build project
+Build project
+-------------
 
 ```shell
 poetry build
 ```
 
-## Lint project
+Lint project
+------------
 
 ```shell
 poetry run flake8
 ```
 
-## Run Tests
+Run Tests
+---------
 
 ```shell
 poetry run pytest