Example python-cerberus validation of configuration file, both in yaml syntax

configuration_validation.yaml

---
enabled:
  required: True
  type: boolean
  empty: False

website_url: 
  required: True
  type: string
  empty: False

lt: 
  required: False
lv: 
  required: False
ea:
  required: False
tc:
  required: False

allowed_element_actions:  
  allowed: &allowed_element_actions
  - click
  - send keys
  - select menu
  - inner text
  - null

allowed_locator_types:
  allowed: &allowed_locator_types
  - id
  - css selector
  - link text
  - partial link text
  - tag name
  - xpath

login_steps: 
  required: True
  type: dict
  empty: False
  schema:
    
    credential_input_1: &element_rules
      required: True
      type: dict
      empty: False
      schema:
        locator_value: &locator_value
          required: True
          type: string
          empty: False
        locator_type: &locator_type
          required: True
          type: string
          empty: False
          allowed: *allowed_locator_types
        element_action: &element_action
          required: True
          type: string
          empty: False
          nullable: True
          allowed: *allowed_element_actions
        text_content: &text_content
          required: True
          type: string
          empty: False
          nullable: True
    
    credential_input_2:
      *element_rules
    
    credential_submit:
      *element_rules
    
    security_questions:
      required: True
      type: dict
      allow_unknown: True
      nullable: True
      valueschema: 
        type: dict
        empty: False
        schema:
          locator_value: 
            *locator_value
          locator_type: 
            *locator_type
          element_action: 
            *element_action
          text_content: 
            required: True
            type: string
            empty: False
            nullable: False

    multifactor_authentication:
      required: True
      type: dict
      allow_unknown: True
      nullable: True
      valueschema: 
        type: dict
        empty: False
        schema:
          
          locator_value: 
            *locator_value
          
          locator_type: 
            *locator_type
          
          element_action: 
            *element_action
          
          text_content: 
            required: True
            type: string
            empty: False
            nullable: False


login_verification_steps:
  required: True
  type: dict
  empty: False
  schema:

    login_success:
      *element_rules
    
    login_failure:
      *element_rules

payment_steps:
  required: True
  type: dict
  empty: False
  allow_unknown: True
  schema:

    payment_type:
      required: True
      empty: False
      type: dict
      anyof:
      - payment_card
      - account_transfer
      schema:

        payment_card:
          required: False
          type: dict
          schema:

            friendly_name:
              required: True
              empty: False
              type: string

            last_four:
              required: True
              empty: False
              type: string

            expiration_date:
              required: True
              empty: False
              type: string

            fill_card_number:
              *element_rules

            fill_expiration_month:
              *element_rules

            fill_expiration_year:
              *element_rules
            
            fill_cvc:
              *element_rules
        
        account_transfer:
          required: False
          empty: False

    transfer_amount:
      required: True
      type: dict
      empty: False
      schema:
        locator_value:
          *locator_value
        locator_type:
          *locator_type
        element_action:
          required: True
          type: string
          empty: False
          nullable: True
          allowed: *allowed_element_actions
        text_content:
          required: True
          type: float
          empty: False
          nullable: True
    commit_payment: 
      *element_rules
  valueschema: 
    type: dict
    empty: False
    schema:
      locator_value: 
        *locator_value
      locator_type: 
        *locator_type
      element_action: 
        *element_action
      text_content: 
        required: True
        empty: False
        nullable: True

confirmation_steps:
  required: True
  type: dict
  empty: False
  schema:
    confirmation_element:
      *element_rules

logout_steps:
  required: True
  type: dict
  empty: False
  schema:
    logout_element:
      *element_rules

logout_verification_steps:
  required: True
  type: dict
  empty: False
  schema:
    logout_verification_element: 
      *element_rules

enc_pass: 
  required: False
  type: string
  empty: False

sample_configuration.yaml

---
# The payment for this website will be executed if True, and will be skipped if False.
enabled: true

# This URL needs to be the full domain name, including the http(s) schema
website_url: https://www.ncsecu.org/ 

# These 4 aliases are defined here to simplify the rest of the document.
# They are used like *lt, *lv, etc, to allow for uniform indentation.
# They are not required, but thye do make the document much easier to read.
lt: &lt locator_type
lv: &lv locator_value
ea: &ea element_action
tc: &tc text_content

# List out the required elements on the page that are needed to login.
login_steps:

  # This is usually the Username field for a traditional username/password login form.
  credential_input_1:

    # The value to use to find the element on the page.
    *lv: userIDHome
    
    # The type of locator, such as xpath, css selector, or id / class / name, etc
    *lt: id  

    # The action to be taken on the element.
    *ea: send_keys

    # This is any text that is needed by the 'element_action' (aka *ea), usually text to locate, click or copy.
    *tc: user87

  # If the second credential is a password, DO NOT include it here.  
  credential_input_2:
    *lv: userPasswordHome
    *lt: id
    *ea: send_keys
    *tc: null # should ALWAYS be null for a password; password is handled internally by the application.

  # IMPORTANT: if this *lv is null, the app attempts to use the 'return' key to submit the login credentials.
  credential_submit:
    *lv: .button[type="submit"]
    *lt: css_selector
    *ea: click
    *tc: null

# How do we know if we logged in ssuccessfully??
login_verification_steps:

  # We look for an element on the page to verify!
  login_success:
    *lv: CheckingSavingsMoneyMarket_0
    *lt: id
    *ea: null
    *tc: null

  # We ALSO must look for an element that verifies unsuccessful login...
  login_failure:
    *lv: ucLogin_tcUserID
    *lt: id
    *ea: null
    *tc: null

security_questions:
  # This section (name) must be included, but can be empty if there are no security questions.
  # Note: Security answers will be collected by the app at runtime. Each question here will prompt an answer on first run.

multifactor_authentication:
  # This section (name) must be included, but can be empty if there is no other authentication factors.
  # Note: Some MFA may not be something that can be automated, but it's safer to use it than to turn it off!!
  # You can handle it manually if you are watching the automation in a non-headless mode. Default timeout for finding elements is 30 seconds, but you can make this longer if you need to!


# Any and all steps required to 'automate' the rest of the payment steps.
# Include as many clicks and form fills (using anything from the list of supported 'element actions.'
payment_steps:
  move_money:
    *lv: 'Move Money'
    *lt: link_text
    *ea: click
    *tc: null
  from_account:
    *lv: ddlFrom
    *lt: id
    *ea: select_menu
    *tc: 12345678
  to_account:
    *lv: ddlTo
    *lt: id
    *ea: select_menu
    *tc: 11234567
  transfer_amount:
    *lv: ucAmount_tcCurrency
    *lt: id
    *ea: send_keys
    *tc: 950.0
  continue_btn: &continue
    *lv: btnContinue
    *lt: id
    *ea: click
    *tc: null
  payment_type:
    *lv: ddlMortgage
    *lt: id
    *ea: click
    *tc: Regular

  # Sometimes you need to hit the 'continue' button a lot... see section following &continue above.
  # so feel free to create your own aliases. Created with &name, used with *name.
  submit_payment_type: *continue
  commit_payment: *continue

# You will most likely want proof of your payment, so here are steps to capture the evidence.
confirmation_steps:
  confirmation_element:
    *lv: /html/body/table/tbody/tr[1]/td/table[2]/tbody/tr[2]/td[1]/form/table/tbody/tr[5]/td/table[1]/tbody/tr[7]/td[3]
    *lt: xpath

    # inner text as the action for 'confirmation_element' will capture and save the text that is located with the *lv.
    *ea: inner_text
    *tc: null

# Element(s) and actions for logging out...
logout_steps:
  logout_element:
    *lv: ctl00_logoutLink
    *lt: id
    *ea: click
    *tc: null

# And verification that we logged out successfully.
logout_verification_steps:
  logout_verification_element: 
    *lv: formLogout
    *lt: id
    *ea: null
    *tc: null