def generate(): #columns = petl.util.base.header(table) data = petl.convertnumbers(table) for row in petl.util.base.dicts(data): #Process blades here for b in blades['post']: row = b.run(row, meta) yield json.dumps(row)+'\n'
table11 = convert(table1)
table11['foo'] = 'lower'
table11['bar'] = float
table11['baz'] = lambda v: v*2
look(table11)
# convertnumbers
table1 = [['foo', 'bar', 'baz', 'quux'],
['1', '3.0', '9+3j', 'aaa'],
['2', '1.3', '7+2j', None]]
from petl import convertnumbers, look
look(table1)
table2 = convertnumbers(table1)
look(table2)
# addfield
table1 = [['foo', 'bar'],
['M', 12],
['F', 34],
['-', 56]]
from petl import addfield, look
look(table1)
# using a fixed value
table2 = addfield(table1, 'baz', 42)
look(table2)
table11 = convert(table1)
table11['foo'] = 'lower'
table11['bar'] = float
table11['baz'] = lambda v: v*2
look(table11)
# convertnumbers
table1 = [['foo', 'bar', 'baz', 'quux'],
['1', '3.0', '9+3j', 'aaa'],
['2', '1.3', '7+2j', None]]
from petl import convertnumbers, look
look(table1)
table2 = convertnumbers(table1)
look(table2)
# addfield
table1 = [['foo', 'bar'],
['M', 12],
['F', 34],
['-', 56]]
from petl import addfield, look
look(table1)
# using a fixed value
table2 = addfield(table1, 'baz', 42)
look(table2)
# multiple conversions can be specified at the same time
table9 = etl.convert(table1, {'foo': 'lower',
'bar': float,
'baz': lambda v: v * 2})
table9
# ...or alternatively via a list
table10 = etl.convert(table1, ['lower', float, lambda v: v*2])
table10
# conversion can be conditional
table11 = etl.convert(table1, 'baz', lambda v: v * 2,
where=lambda r: r.foo == 'B')
table11
# conversion can access other values from the same row
table12 = etl.convert(table1, 'baz',
lambda v, row: v * float(row.bar),
pass_row=True)
table12
# convertnumbers()
##################
import petl as etl
table1 = [['foo', 'bar', 'baz', 'quux'],
['1', '3.0', '9+3j', 'aaa'],
['2', '1.3', '7+2j', None]]
table2 = etl.convertnumbers(table1)
table2
import petl as etl
table_header = [
"Fixed Acidity", "Volatile Acidity", "Citric Acid", "Sugar", "Chlorides",
"Free SO2", "Total SO2", "Density", "pH", "Sulfates", "Alcohol", "Quality"
]
table1 = etl.addfield(
etl.convertnumbers(
etl.setheader(etl.fromcsv('winequality-red.csv'), table_header)),
"Type", "Red")
table2 = etl.addfield(
etl.convertnumbers(
etl.setheader(etl.fromcsv('winequality-white.csv'), table_header)),
"Type", "White")
#print(etl.head(table1))
#print(etl.head(table2))
table1_filtered = etl.select(table1, "Quality", lambda v: v > 6)
table2_filtered = etl.select(table2, "Quality", lambda v: v > 4)
good_wines = etl.cat(table1_filtered, table2_filtered)
good_wines_enhanced = etl.addfields(
good_wines,
[("Max Acidity",
lambda rec: rec["Fixed Acidity"] + rec["Volatile Acidity"]),
("Locked SO2", lambda rec: rec["Total SO2"] - rec["Free SO2"])])
#print(etl.head(good_wines_enhanced))
#print(etl.tail(good_wines_enhanced))
