Add default frictionless CLI command

[roll]

Overview

Currently, we have these commands:

• frictionless describe
• frictionless extract
• frictionless validate
• [coming] frictionless analyze
• etc

We'd like to have (note there is no action):

$ frictionless table.csv

# Describe

[resource/schema as a table]

# Extract

[first X lines of the data as a table]

# Validate

## Summary

[validation summary table]

## Errors 

[validation errors table]

[shashigharti]

@roll if user doesn't mention the action, it will run all three possible actions and show the results?

[roll]

@shashigharti
It needs to be a new CLI command e.g. program.default:

resource = Resource('tabe.csv')
resource.infer()

# show schema as a table using resource.schema (let's prototype and discuss)

# show first X rows as a table using resource.extract

# show validation report using resource.validate

We don't need a new frictionless.actions for it -- just a new module in program

[shashigharti]

@roll resource.schema.fields will not be nested in this usecase?

And to flatten json object what do you think of this library https://pypi.org/project/flatten-json/?

[roll]

@shashigharti
Our goal is provide the most vital information regarding the schema, for example:

# Describe

field type required
-------------------
name1 string 
name2 number true
...

[roll]

Currently, it doesn't seem to be possible to provide a default command the way we want with Typer - fastapi/typer#18

We will implement a normal command "summary" - frictionless summary table.csv - and then @roll will think how we can call it also as the default

[roll]

@shashigharti
As a current quick-fix:

you can use this in `program.main' for program creation

# Program


# TODO: remove this hack when Typer supports not-found commands catching
# <link to the typer issue>
class Program(typer.Typer):
    def __call__(self, *args, **kwargs):
        if sys.argv[1].count("."):
            sys.argv = [sys.argv[0], "summary", sys.argv[1]]
        return super().__call__(*args, **kwargs)


program = Program()

Can you please also create a feature request for Typer? I would say that we'd like to have an ability to catch not found commands or something like this