Deep Update

Contents

Deep Update#

Introduction#

A method to merge two objects, named source and override, use override to modify source data.

Usage#

The source should be a dict or a list. The override must be a dict, or we will return the override directly.

When the source is a dict#

delete key#

Use the __delete__ keyword to delete keys in source, True for delete all, str or List[str] for specific keys.

For example (using yaml to present python dict).

# source
config:
    A:
        abc: 1
    B:
        a: d
        b: e
    C:
        A: a
        B: b
        C: c

# override
config:
    A:
        __delete__: true
    B:
        __delete__: b
    C:
        __delete__: [ A, B ]

# result
config:
    A: {}
    B:
        a: d
    C:
        C: c

add key and modify key#

Just write the key-value pair to add or modify context in the source.

For example (using yaml to present python dict).

# source
config:
    A:
        abc: 1
    B:
        a: d
        b: e

# override
config:
    A:
        abc: 2
    B:
        c: c
    C:
        a: A

# result
config:
    A:
        abc: 2
    B:
        a: d
        b: e
        c: c
    C:
        a: A

When the source is a list#

delete item#

Use the __delete__ keyword to delete items in the source, True for delete all, int or List[int] for specific items, and negative int for counting from the end.

For example (using yaml to present python dict).

# source
config:
    A:
        - abc
        - efg
    B:
        - 123
        - 234
    C: [ a, b, c ]

# override
config:
    A:
        __delete__: true
    B:
        __delete__: 0
    C:
        __delete__: [ 0, -1 ]

# result
config:
    A: []
    B:
        - 234
    C:
        - b

modify item#

Use the change_item keyword to modify items in the source, the value of it must be List[List[index, item]]. It will change every item at the index to the corresponding item.

For example (using yaml to present python dict).

# source
config:
    A:
        - abc
        - efg
    B: [ a, b, c ]

# override
config:
    A:
        change_item:
            - [ 0, A ]
    B:
        change_item:
            - [ -1, B ]
            - [ 0, C ]

# result
config:
    A:
        - A
        - efg
    B: [ C, b, B ]

add items#

pre items#

Use the pre_item keyword to add items to the beginning of the source, the value of it must be an item or a list. If the value is a list, every item in it will be added to the beginning of the source, otherwise, add the value to the beginning of the source.

For example (using yaml to present python dict).

# source
config:
    A:
        - abc
        - efg
    B: [ a, b, c ]

# override
config:
    A:
        pre_item: A
    B:
        pre_item: [ B, C ]

# result
config:
    A:
        - A
        - abc
        - efg
    B:
        - B
        - C
        - a
        - b
        - c

post items#

Use the post_item keyword to add items to the end of the source. The value of it must be an item or a list. If the value is a list, every item in it will be added to the end of the source, otherwise, we will add the value to the source.

For example (using yaml to present python dict).

# source
config:
    A:
        - abc
        - efg
    B: [ a, b, c ]

# override
config:
    A:
        post_item: A
    B:
        post_item: [ B, C ]

# result
config:
    A:
        - abc
        - efg
        - A
    B:
        - a
        - b
        - c
        - B
        - C

insert items#

Use the insert_item keyword to insert items to the source. The value of it must be List[List[index, item] or List[index, item, extend]], we will insert the item or the list of items to the position specified by the index. If the index is bigger or equal to the len of the source or smaller than the -len of the source, this will work as post_item and pre_item. The extend is a bool to indicate whether the item is a list of items or not. If it is set to True, the elements of the item will be inserted one by one and if it is set to False, the item will be treated as an element and will be inserted to the source. You can omit it when it is False. This works well with __delete__` and multiple inserts, the insert order and delete index will be calculated automatically.

For example (using yaml to present python dict).

# source
config:
    A:
        - abc
        - efg
    B: [ a, b, c ]
    C: [ 1, 2, 3, 4 ]
    D: [ 1, 2, 3, 4 ]
    E: [ 1, 2, 3, 4 ]

# override
config:
    A:
        insert_item:
            - [ 0, A ]
            - [ 1, B ]
    B:
        insert_item:
            - [ -1, B ]
            - [ 1, [ 1, 2, 3 ], true ]
    C:
        insert_item:
            - [ -5, A ]
            - [ 4, B ]
            - [ 5, C ]
    D:
        __delete__: [ 1, 2 ]
        insert_item:
            - [ 0, A ]
            - [ 3, B ]
            - [ 1, [ C, D ], true ]
    E:
        __delete__: true
        insert_item:
            - [ 0, A ]
            - [ 3, B ]
            - [ 1, [ C, D ], true ]

# result
config:
    A:
        - A
        - abc
        - B
        - efg
    B:
        - a
        - 1
        - 2
        - 3
        - b
        - B
        - c
    C: [ A, 1, 2, 3, 4, B, C]
    D: [ A, 1, C, D, B, 4 ]
    E: [ A, C, D, B ]

All Keywords#

keyword	value	effect
`__delete__`	`True` or `str,int` or `list[str,int]`,`True` for delete all keys from other config, `str,int` only delete the specific key (for dict) or index (for list)	Delete some part of config from other.
`change_item`	`list[[index, item]]`,used only when merge list	Add ability of merg list, change the `list[index]` from other to `item`
`insert_item`	`list[[index, item, (extend)]]`,used only when merge list	Add ability of merg list, insert item to the `list` at `index`, extend=True if insert a list of items
`pre_item`	`Any`or `list[Any]`,used only when merge list	Add ability of merg list, add the value in the start of the list from other to item
`post_item`	`Any`or `list[Any]`,used only when merge list	Add ability of merg list, add the value in the end of the list from other to item