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![https://tools.ietf.org/html/rfc5870
geo-URI = geo-scheme ":" geo-path
geo-scheme = "geo"
geo-path = coordinates p
coordinates = num "," num [ "," num ]
p = [ crsp ] [ uncp ] [";" other]...
crsp = ";crs=" crslabel
crslabel = "wgs84" / labeltext
uncp = ";u=" uval
other = labeltext "=" val
val = uval / chartext
Best practice:
Start with a BNF](https://image.slidesharecdn.com/pyparsingtalk1-160815151722/75/Writing-Parsers-in-Python-using-Pyparsing-7-2048.jpg)
![patt = r'geo:(-?d+(?:.d*)?),(-?d+(?:.d*)?)(?:,(-?d+(?:.d*)?))?' +
r'(?:;(crs=[^;]+))?(?:;(u=d+(?:.d*)?))?'
print(re.compile(patt).match(tests[0]).groups())
('27.9878', '86.9250', '8850', 'crs=wgs84', 'u=100')
ParseResult(scheme='geo', netloc='',
path='27.9878,86.9250,8850;crs=wgs84;u=100', params='',
query='', fragment='')](https://image.slidesharecdn.com/pyparsingtalk1-160815151722/75/Writing-Parsers-in-Python-using-Pyparsing-8-2048.jpg)
![from pyparsing import *
EQ,COMMA = map(Suppress, "=,")
number = Regex(r'-?d+(.d*)?').addParseAction(lambda t: float(t[0]))
geo_coords = Group(number('lat') + COMMA + number('lng') +
Optional(COMMA + number('alt')))
crs_arg = Group('crs' + EQ + Word(alphanums))
u_arg = Group('u' + EQ + number)
url_args = Dict(delimitedList(crs_arg | u_arg, ';'))
geo_url = "geo:" + geo_coords('coords') + Optional(';' + url_args('args'))
Best practice:
Use parse actions for conversions
Best practice:
Use results names](https://image.slidesharecdn.com/pyparsingtalk1-160815151722/75/Writing-Parsers-in-Python-using-Pyparsing-9-2048.jpg)
![geo:36.246944,-116.816944,-85;u=50
['geo:', [36.246944, -116.816944, -85.0], ';', [['u', 50.0]]]
- args: [['u', 50.0]]
- u: 50.0
- coords: [36.246944, -116.816944, -85.0]
- alt: -85.0
- lat: 36.246944
- lng: -116.816944
geo:30.2644663,-97.7841169;a=100;href=http://www.allure-energy.com/
['geo:', [30.2644663, -97.7841169]]
- coords: [30.2644663, -97.7841169]
- lat: 30.2644663
- lng: -97.7841169](https://image.slidesharecdn.com/pyparsingtalk1-160815151722/75/Writing-Parsers-in-Python-using-Pyparsing-11-2048.jpg)
![from pyparsing import *
EQ,COMMA = map(Suppress, "=,")
number = Regex(r'-?d+(.d*)?').addParseAction(lambda t: float(t[0]))
geo_coords = Group(number('lat') + COMMA + number('lng') +
Optional(COMMA + number('alt')))
crs_arg = Group('crs' + EQ + Word(alphanums))
u_arg = Group('u' + EQ + number)
other = Group(Word(alphas) + EQ + CharsNotIn(';'))
url_args = Dict(delimitedList(crs_arg | u_arg | other, ';'))
geo_url = "geo:" + geo_coords('coords') + Optional(';' + url_args('args'))](https://image.slidesharecdn.com/pyparsingtalk1-160815151722/75/Writing-Parsers-in-Python-using-Pyparsing-12-2048.jpg)
![geo:36.246944,-116.816944,-85;u=50
['geo:', [36.246944, -116.816944, -85.0], ';', [['u', 50.0]]]
- args: [['u', 50.0]]
- u: 50.0
- coords: [36.246944, -116.816944, -85.0]
- alt: -85.0
- lat: 36.246944
- lng: -116.816944
geo:30.2644663,-97.7841169;a=100;href=http://www.allure-energy.com/
['geo:', [30.2644663, -97.7841169], ';',
[['a', '100'], ['href', 'http://www.allure-energy.com/']]]
- args: [['a', '100'], ['href', 'http://www.allure-energy.com/']]
- a: 100
- href: http://www.allure-energy.com/
- coords: [30.2644663, -97.7841169]
- lat: 30.2644663
- lng: -97.7841169](https://image.slidesharecdn.com/pyparsingtalk1-160815151722/75/Writing-Parsers-in-Python-using-Pyparsing-13-2048.jpg)
![geo = geo_url.parseString('geo:27.9878,86.9250,8850;crs=wgs84;u=100')
print(geo.dump())
['geo:', [27.9878, 86.925, 8850.0], ';', [['crs', 'wgs84'], ['u', 100.0]]]
- args: [['crs', 'wgs84'], ['u', 100.0]]
- crs: wgs84
- u: 100.0
- coords: [27.9878, 86.925, 8850.0]
- alt: 8850.0
- lat: 27.9878
- lng: 86.925
print(geo.coords.alt)
8850.0
print(geo.args.asDict())
{'crs': 'wgs84', 'u': 100.0}
Best practice:
dump() is very useful for seeing the
structure and names in the parsed
results
Best practice:
pprint() is useful for seeing the results
structure if no results names are
defined](https://image.slidesharecdn.com/pyparsingtalk1-160815151722/75/Writing-Parsers-in-Python-using-Pyparsing-14-2048.jpg)
![http://www.enodev.fr/
LC
TD 90 AV 60
TD 90 AV 80
BC
REPETE 4 [ TG 90 AV 20 ]
LC
AV 80
BC
REPETE 4 [ AV 20 TG 90 ]](https://image.slidesharecdn.com/pyparsingtalk1-160815151722/75/Writing-Parsers-in-Python-using-Pyparsing-18-2048.jpg)
Writing Parsers in Python using Pyparsing
- 1. Paul McGuire APUG –May, 2016 WritingParsersinPython UsingPyparsing WritingParsersinPython UsingPyparsing Paul McGuire APUG – May, 2016
- 2. Best practices: … highlightedin the examples
- 4. integer = Word('0123456789') phone_number= Optional('(' + integer + ')') + integer + '-' + integer # re.compile(r'((d+))?d+-d+') greet = Word(alphas) + "," + Word(alphas) + "!" greet.parseString("Hello, World!") Best practice: Don’t include whitespace in the parser definition
- 6.
- 7. https://tools.ietf.org/html/rfc5870 geo-URI = geo-scheme":" geo-path geo-scheme = "geo" geo-path = coordinates p coordinates = num "," num [ "," num ] p = [ crsp ] [ uncp ] [";" other]... crsp = ";crs=" crslabel crslabel = "wgs84" / labeltext uncp = ";u=" uval other = labeltext "=" val val = uval / chartext Best practice: Start with a BNF
- 8. patt = r'geo:(-?d+(?:.d*)?),(-?d+(?:.d*)?)(?:,(-?d+(?:.d*)?))?'+ r'(?:;(crs=[^;]+))?(?:;(u=d+(?:.d*)?))?' print(re.compile(patt).match(tests[0]).groups()) ('27.9878', '86.9250', '8850', 'crs=wgs84', 'u=100') ParseResult(scheme='geo', netloc='', path='27.9878,86.9250,8850;crs=wgs84;u=100', params='', query='', fragment='')
- 9. from pyparsing import* EQ,COMMA = map(Suppress, "=,") number = Regex(r'-?d+(.d*)?').addParseAction(lambda t: float(t[0])) geo_coords = Group(number('lat') + COMMA + number('lng') + Optional(COMMA + number('alt'))) crs_arg = Group('crs' + EQ + Word(alphanums)) u_arg = Group('u' + EQ + number) url_args = Dict(delimitedList(crs_arg | u_arg, ';')) geo_url = "geo:" + geo_coords('coords') + Optional(';' + url_args('args')) Best practice: Use parse actions for conversions Best practice: Use results names
- 10. tests = """ geo:36.246944,-116.816944,-85;u=50 geo:30.2644663,-97.7841169;a=100;href=http://www.allure-energy.com/ """ geo_url.runTests(tests) assertgeo_url.matches("geo:36.246944,-116.816944,-85;u=50“) assert geo_url.matches("geo:36.246944;u=50“) Best practice: runTests() is new in 2.0.4 Best practice: Use matches() for incremental inline validation of your parser elements
- 11. geo:36.246944,-116.816944,-85;u=50 ['geo:', [36.246944, -116.816944,-85.0], ';', [['u', 50.0]]] - args: [['u', 50.0]] - u: 50.0 - coords: [36.246944, -116.816944, -85.0] - alt: -85.0 - lat: 36.246944 - lng: -116.816944 geo:30.2644663,-97.7841169;a=100;href=http://www.allure-energy.com/ ['geo:', [30.2644663, -97.7841169]] - coords: [30.2644663, -97.7841169] - lat: 30.2644663 - lng: -97.7841169
- 12. from pyparsing import* EQ,COMMA = map(Suppress, "=,") number = Regex(r'-?d+(.d*)?').addParseAction(lambda t: float(t[0])) geo_coords = Group(number('lat') + COMMA + number('lng') + Optional(COMMA + number('alt'))) crs_arg = Group('crs' + EQ + Word(alphanums)) u_arg = Group('u' + EQ + number) other = Group(Word(alphas) + EQ + CharsNotIn(';')) url_args = Dict(delimitedList(crs_arg | u_arg | other, ';')) geo_url = "geo:" + geo_coords('coords') + Optional(';' + url_args('args'))
- 13. geo:36.246944,-116.816944,-85;u=50 ['geo:', [36.246944, -116.816944,-85.0], ';', [['u', 50.0]]] - args: [['u', 50.0]] - u: 50.0 - coords: [36.246944, -116.816944, -85.0] - alt: -85.0 - lat: 36.246944 - lng: -116.816944 geo:30.2644663,-97.7841169;a=100;href=http://www.allure-energy.com/ ['geo:', [30.2644663, -97.7841169], ';', [['a', '100'], ['href', 'http://www.allure-energy.com/']]] - args: [['a', '100'], ['href', 'http://www.allure-energy.com/']] - a: 100 - href: http://www.allure-energy.com/ - coords: [30.2644663, -97.7841169] - lat: 30.2644663 - lng: -97.7841169
- 14. geo = geo_url.parseString('geo:27.9878,86.9250,8850;crs=wgs84;u=100') print(geo.dump()) ['geo:',[27.9878, 86.925, 8850.0], ';', [['crs', 'wgs84'], ['u', 100.0]]] - args: [['crs', 'wgs84'], ['u', 100.0]] - crs: wgs84 - u: 100.0 - coords: [27.9878, 86.925, 8850.0] - alt: 8850.0 - lat: 27.9878 - lng: 86.925 print(geo.coords.alt) 8850.0 print(geo.args.asDict()) {'crs': 'wgs84', 'u': 100.0} Best practice: dump() is very useful for seeing the structure and names in the parsed results Best practice: pprint() is useful for seeing the results structure if no results names are defined
- 15. https://bitbucket.org/mchaput/whoosh/overview TrafficLight = { Red-> Green; Green -> Yellow; Yellow -> Red; } DocumentRevision = { New -( create )-> Editing; Editing -( cancel )-> Deleted; Editing -( submit )-> PendingApproval; PendingApproval -( reject )-> Editing; PendingApproval -( approve )-> Approved; Approved -( activate )-> Active; Active -( deactivate )-> Approved; Approved -( retire )-> Retired; Retired -( purge )-> Deleted; }
- 16.
- 17. https://iusb.edu/computerscience/faculty-and- staff/faculty/jwolfer/005.pdf rinit # initializecommunication rsens Rd # read robot sensors rspeed Rright,Rleft # set robot motor speeds rspeed $immed,$immed Crumble http://redfernelectronics.co.uk
- 18. http://www.enodev.fr/ LC TD 90 AV60 TD 90 AV 80 BC REPETE 4 [ TG 90 AV 20 ] LC AV 80 BC REPETE 4 [ AV 20 TG 90 ]
- 19.