dm.selectors.row package¶
Submodules¶
dm.selectors.row.AbstractTableRowSelector module¶
Abstract class for one value selector.
Selector can select value based on given time from a table.
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class
dm.selectors.row.AbstractTableRowSelector.
AbstractRowSelector
(con, table_name)¶ Bases:
dm.selectors.AbstractSelector.AbstractSelector
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abstract
row
(column_name, time)¶ It selects one row from source.
- Parameters
column_name – name of column that contains required values
time – timestamp of required data
- Returns
data from the column in given time
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abstract
dm.selectors.row.CachedDiffRowWithIntervalSelector module¶
Cached row selector for selection of differences of values.
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class
dm.selectors.row.CachedDiffRowWithIntervalSelector.
CachedDiffRowWithIntervalSelector
(con, table_name, start, end)¶ Bases:
dm.selectors.row.CachedRowWithIntervalSelector.CachedRowWithIntervalSelector
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row
(column_name, time)¶ It selects one row from cache.
It also performs difference between two obtained values.
- Parameters
column_name – name of column that contains required values
time – timestamp of required data
- Returns
data from the column in given time
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dm.selectors.row.CachedRowWithIntervalSelector module¶
Cached interval selector from database.
Selector can select given intervals of values from a given table and selected rows are stored into cache.
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class
dm.selectors.row.CachedRowWithIntervalSelector.
CachedRowWithIntervalSelector
(con, table_name, start, end)¶ Bases:
dm.selectors.row.SimpleCachedRowSelector.SimpleCachedRowSelector
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row
(column_name, time)¶ It selects one row from cache.
If the method is called for the first time, cache will be initialized.
- Parameters
column_name – name of column that contains required values
time – timestamp of required data
- Returns
data from the column in given time
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dm.selectors.row.LinearSimpleCachedRowSelector module¶
dm.selectors.row.SimpleCachedRowSelector module¶
Cached selector for one value from database.
Selector can select value based on given time from a table in database and selected values are stored in cache.
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class
dm.selectors.row.SimpleCachedRowSelector.
SimpleCachedRowSelector
(con, table_name)¶ Bases:
dm.selectors.row.AbstractTableRowSelector.AbstractRowSelector
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row
(column_name, time)¶ It selects one row from cache or database.
If the method is called for the first time, cache will be initialized. The second call of the method returns loaded data stored in cache.
- Parameters
column_name – name of column that contains required values
time – timestamp of required data
- Returns
data from the column in given time
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