1
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""" |
2
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Usefull method and classes not belonging anywhere and depending on opcua library |
3
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""" |
4
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5
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from dateutil import parser |
6
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from datetime import datetime |
7
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from enum import Enum, IntEnum |
8
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9
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from opcua import ua |
10
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11
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12
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def val_to_string(val): |
13
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""" |
14
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convert a python object or python-opcua object to a string |
15
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which should be easy to understand for human |
16
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easy to modify, and not too hard to parse back ....not easy |
17
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meant for UI or command lines |
18
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19
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""" |
20
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if isinstance(val, (list, tuple)): |
21
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res = [] |
22
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for v in val: |
23
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res.append(val_to_string(v)) |
24
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return "[" + ", ".join(res) + "]" |
25
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26
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if hasattr(val, "to_string"): |
27
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val = val.to_string() |
28
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elif isinstance(val, ua.StatusCode): |
29
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val = val.name |
30
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elif isinstance(val, (Enum, IntEnum)): |
31
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val = val.name |
32
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elif isinstance(val, ua.DataValue): |
33
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val = variant_to_string(val.Value) |
34
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elif isinstance(val, str): |
35
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pass |
36
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elif isinstance(val, bytes): |
37
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val = str(val) |
38
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elif isinstance(val, datetime): |
39
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val = val.isoformat() |
40
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elif isinstance(val, (int, float)): |
41
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val = str(val) |
42
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else: |
43
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# FIXME: Some types are probably missing! |
44
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val = str(val) |
45
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return val |
46
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47
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48
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def variant_to_string(var): |
49
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""" |
50
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convert a variant to a string which should be easy to understand for human |
51
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easy to modify, and not too hard to parse back ....not easy |
52
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meant for UI or command lines |
53
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""" |
54
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return val_to_string(var.Value) |
55
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56
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57
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def string_to_val(string, vtype): |
58
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""" |
59
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Convert back a string to a python or python-opcua object |
60
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""" |
61
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string = string.strip() |
62
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if string.startswith("["): |
63
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string = string[1:-1] |
64
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var = [] |
65
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for s in string.split(","): |
66
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s = s.strip() |
67
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val = string_to_val(s, vtype) |
68
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var.append(val) |
69
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return var |
70
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71
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if vtype == ua.VariantType.Null: |
72
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val = None |
73
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elif vtype == ua.VariantType.Boolean: |
74
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val = bool(string) |
75
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elif 4 <= vtype.value < 9: |
76
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val = int(string) |
77
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elif vtype in (ua.VariantType.Float, ua.VariantType.Double): |
78
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val = float(string) |
79
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elif vtype in (ua.VariantType.String, ua.VariantType.XmlElement): |
80
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val = string |
81
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elif vtype in (ua.VariantType.SByte, ua.VariantType.Guid, ua.VariantType.ByteString): |
82
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val = bytes(string) |
83
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elif vtype in (ua.VariantType.NodeId, ua.VariantType.ExpandedNodeId): |
84
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val = ua.NodeId.from_string(string) |
85
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elif vtype == ua.VariantType.QualifiedName: |
86
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val = ua.QualifiedName.from_string(string) |
87
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elif vtype == ua.VariantType.DateTime: |
88
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val = parser.parse(string) |
89
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elif vtype == ua.VariantType.LocalizedText: |
90
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val = ua.LocalizedText(string) |
91
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elif vtype == ua.VariantType.StatusCode: |
92
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val = ua.StatusCode(string) |
93
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else: |
94
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# FIXME: Some types are probably missing! |
95
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raise NotImplementedError |
96
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return val |
97
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98
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99
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def string_to_variant(string, vtype): |
100
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""" |
101
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convert back a string to an ua.Variant |
102
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""" |
103
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return ua.Variant(string_to_val(string, vtype), vtype) |
104
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105
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106
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