description: Implementation of slice.
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Implementation of slice.
The slice operation is meant to replicate the slicing of a list in python.
Slicing a list in python is done by specifying a beginning and ending. The resulting list consists of all elements in the range.
x = ['a', 'b', 'c', 'd', 'e', 'f', 'g'] print(x[2:5]) # all elements between index 2 inclusive and index 5 exclusive ['c', 'd', 'e'] print(x[2:]) # all elements between index 2 and the end. ['c', 'd', 'e', 'f', 'g'] print(x[:4]) # all elements between the beginning and index 4 (exclusive). ['a', 'b', 'c', 'd'] print(x[-3:-1]) # all elements starting three from the end. # until one from the end (exclusive). ['e', 'f'] print(x[-3:6]) # all elements starting three from the end # until index 6 exclusive. ['e', 'f', 'g']
over the elements (e.g. x[2:6:2]=['c', 'e'], giving you every other element. This is not implemented.
A prensor can be considered to be interleaved lists and dictionaries. E.g.:
my_expression = [{
"foo":[
{"bar":[
{"baz":["a","b","c", "d"]},
{"baz":["d","e","f"]}
]
},
{"bar":[
{"baz":["g","h","i"]},
{"baz":["j","k","l", ]}
{"baz":["m"]}
]
}]
}]
result_1 = slice_expression.slice_expression(
my_expression, "foo.bar", "new_bar",begin=1, end=3)
result_1 = [{
"foo":[
{"bar":[
{"baz":["a","b","c", "d"]},
{"baz":["d","e","f"]}
],
"new_bar":[
{"baz":["d","e","f"]}
]
},
{"bar":[
{"baz":["g","h","i"]},
{"baz":["j","k","l", ]}
{"baz":["m", ]}
],
"new_bar":[
{"baz":["j","k","l", ]}
{"baz":["m", ]}
]
}]
}]
result_2 = slice_expression.slice_expression(
my_expression, "foo.bar.baz", "new_baz",begin=1, end=3)
result_2 = [{
"foo":[
{"bar":[
{"baz":["a","b","c", "d"],
"new_baz":["b","c"],
},
{"baz":["d","e","f"], "new_baz":["e","f"]}
]
},
{"bar":[
{"baz":["g","h","i"], "new_baz":["h","i"]},
{"baz":["j","k","l"], "new_baz":["k","l"]},
{"baz":["m", ]}
]
}]
}]
slice_expression(...): Creates a new subtree with a sliced expression.