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from __future__ import absolute_import, print_function, division
# select()
##########
import petl as etl
table1 = [['foo', 'bar', 'baz'],
['a', 4, 9.3],
['a', 2, 88.2],
['b', 1, 23.3],
['c', 8, 42.0],
['d', 7, 100.9],
['c', 2]]
# the second positional argument can be a function accepting
# a row
table2 = etl.select(table1,
lambda rec: rec.foo == 'a' and rec.baz > 88.1)
table2
# the second positional argument can also be an expression
# string, which will be converted to a function using petl.expr()
table3 = etl.select(table1, "{foo} == 'a' and {baz} > 88.1")
table3
# the condition can also be applied to a single field
table4 = etl.select(table1, 'foo', lambda v: v == 'a')
table4
# selectre()
############
import petl as etl
table1 = [['foo', 'bar', 'baz'],
['aa', 4, 9.3],
['aaa', 2, 88.2],
['b', 1, 23.3],
['ccc', 8, 42.0],
['bb', 7, 100.9],
['c', 2]]
table2 = etl.selectre(table1, 'foo', '[ab]{2}')
table2
# selectusingcontext()
######################
import petl as etl
table1 = [['foo', 'bar'],
['A', 1],
['B', 4],
['C', 5],
['D', 9]]
def query(prv, cur, nxt):
return ((prv is not None and (cur.bar - prv.bar) < 2)
or (nxt is not None and (nxt.bar - cur.bar) < 2))
table2 = etl.selectusingcontext(table1, query)
table2
# facet()
#########
import petl as etl
table1 = [['foo', 'bar', 'baz'],
['a', 4, 9.3],
['a', 2, 88.2],
['b', 1, 23.3],
['c', 8, 42.0],
['d', 7, 100.9],
['c', 2]]
foo = etl.facet(table1, 'foo')
sorted(foo.keys())
foo['a']
foo['c']
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