Feature: add @jinja and @format casting

[EdwardCuiPeacock]

Adding the capability of @jinja and @format templated values to be type-casted

Related to issue: #642

• Implemented the following casting cases that are compatible with @jinja and @format:
  • @str: casting parsed results to string
  • @int: casting parsed results to integer
  • @float: casting parsed results to float
  • @bool: casting parsed results to boolean
  • @json: casting parsed results to dictionary
• Updated Lazy class under utils/parse_conf.py
  • Added the casting argument
  • Adding the method set_casting(self, casting)
• Added the unit test for the above casting.

Examples

Casting to integer from Jinja templated values

NUM_GPUS: 4
# This returns the integer after parsing
FOO: "@int @jinja {{ this.NUM_GPUS }}"
# This returns the string after parsing
FOO: "@jinja {{ this.NUM_GPUS }}"

Casting to a json dict from Jinja templated values

MODEL_1:
  MODEL_PATH: "src.main.models.CNNModel"
  GPU_COUNT: 4
  OPTIMIZER_KWARGS:
    learning_rate: 0.002

MODEL_2:
  MODEL_PATH: "src.main.models.VGGModel"
  GPU_COUNT: 2
  OPTIMIZER_KWARGS:
    learning_rate: 0.001

# Flag to choose which model to use
MODEL_TYPE: "MODEL_2"

# This returns the dict loaded from the resulting json
MODEL_SETTINGS: "@json @jinja {{ this|attr(this.MODEL_TYPE) }}"

# This returns the raw json string
MODEL_SETTINGS: "@jinja {{ this|attr(this.MODEL_TYPE) }}"

[pep8speaks]

Hello @EdwardCuiPeacock! Thanks for updating this PR. We checked the lines you've touched for PEP 8 issues, and found:

There are currently no PEP 8 issues detected in this Pull Request. Cheers! 🍻

Comment last updated at 2022-01-29 17:05:04 UTC

[EdwardCuiPeacock]

@rochacbruno any idea how to fix this error in the CI/CD pipeline? What am I missing?

make: *** [Makefile:192: run-pre-commit] Error 1
Error: Process completed with exit code 2.

Update: used black matching the version and args in the .pre-commit-config.yaml and reformatted parse_conf.py. Not sure if this would fix the problem.

[codecov]

Codecov Report

Merging #704 (4c77cdd) into master (0bca1d0) will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##            master      #704   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           21        21           
  Lines         1671      1684   +13     
=========================================
+ Hits          1671      1684   +13     

Impacted Files	Coverage Δ
dynaconf/utils/parse_conf.py	100.00% <100.00%> (ø)

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