[Python-es] Expresiones regulares
Miguel Angel Rodriguez
marodal en gmail.com
Mar Jun 3 22:55:44 CEST 2014
Este es un ejemplo de lo que recibo:
{"format":"JSON","result":{"devices":[{"key":"SCGDE1BA:180340320","channels":[{"name":"PF","unit":"","meta":"PF","value":"1.000"},{"name":"P-WSpt","unit":"kW","meta":"P-WSpt","value":"935"},
{"name":"Vac","unit":"V","meta":"Vac","value":"217.5"},{"name":"Iac","unit":"A","meta":"Iac","value":"513.8"},{"name":"Pac","unit":"kW","meta":"Pac","value":"335.2"},{"name":"Qac","unit":"kV
Ar","meta":"Qac","value":"-1.0"},{"name":"Sac","unit":"kVA","meta":"Sac","value":"335.1"},{"name":"Fac","unit":"Hz","meta":"Fac","value":"49.950"},{"name":"ErrNoFirst","unit":"","meta":"ErrNoFirst","value":"0"},{"
name":"P-WModFailStt","unit":"","meta":"P-WModFailStt","value":"Off"},{"name":"P-WModStt","unit":"","meta":"P-WModStt","value":"Off"},{"name":"Dsc","unit":"","meta":"Dsc","value":"---"},{"name":"Firmware-9","unit":"","meta":"Firmware-9","value":"
"},{"name":"Cntry","unit":"","meta":"Cntry","value":"DE1"}
,{"name":"Type","unit":"","meta":"Type","value":"SCG"},{"name":"Mode","unit":"","meta":"Mode","value":"Operation"},{"name":"Error","unit":"","meta":"Error","value":"---"}]}]},"version":"1.0"
Quiero parsearlo para poder almacenar en unas variables que tengo los
values que aparecen en el JSON. De esta forma:
Con la solucion con expresiones regulares en cada iteracion tengo lo
siguiente:
d_value = [name,(valor del name),unit,(valor del unit),meta,(valor del
meta),value,(valor del value)]
En esa iteracion hago lo siguiente:
if d_value[1] == "PF":
mi_variable_PF = d_value[7]
if d_value[1] == "Fac":
mi_variable_Fac = d_value[7]
.....
No necesito todos los values, solo los que corresponden a unos determinados
name.
Con la solucion con expresiones regulares tengo el siguiente bug:
Alguna veces en el json aparece "unit":"". Es decir, la clave key no tiene
valor, por lo que obtengo un array de solo 7 elementos (sin el elemento
valor del unit) y consigo recuperar el value para ese name. ¿Alguien me
podría ayudar con esto?
Por ultimo, con la solucion con JSON, ¿es necesario usar ficheros? No se
como será el manejo de ficheros en el sistema donde va a funcionar este
python.
Gracias y un saludo
El 3 de junio de 2014, 22:53, Miguel Angel Rodriguez <marodal en gmail.com>
escribió:
> Este es un ejemplo de lo que recibo:
>
> {"format":"JSON","result":{"devices":[{"key":"SCGDE1BA:
> 180340320","channels":[{"name":"PF","unit":"","meta":"PF","
> value":"1.000"},{"name":"P-WSpt","unit":"kW","meta":"P-WSpt","value":"935"},
> {"name":"Vac","unit":"V","meta":"Vac","value":"217.5"},{
> "name":"Iac","unit":"A","meta":"Iac","value":"513.8"},{"
> name":"Pac","unit":"kW","meta":"Pac","value":"335.2"},{"name":"Qac","unit":"kV
> Ar","meta":"Qac","value":"-1.0"},{"name":"Sac","unit":"kVA"
> ,"meta":"Sac","value":"335.1"},{"name":"Fac","unit":"Hz","
> meta":"Fac","value":"49.950"},{"name":"ErrNoFirst","unit":""
> ,"meta":"ErrNoFirst","value":"0"},{" name":"P-WModFailStt","unit":"
> ","meta":"P-WModFailStt","value":"Off"},{"name":"P-
> WModStt","unit":"","meta":"P-WModStt","value":"Off"},{"
> name":"Dsc","unit":"","meta":"Dsc","value":"---"},{"name":"
> Firmware-9","unit":"","meta":"Firmware-9","value":"
> "},{"name":"Cntry","unit":"","meta":"Cntry","value":"DE1"}
> ,{"name":"Type","unit":"","meta":"Type","value":"SCG"},{"
> name":"Mode","unit":"","meta":"Mode","value":"Operation"},{"
> name":"Error","unit":"","meta":"Error","value":"---"}]}]},"version":"1.0"
>
>
>
> Quiero parsearlo para poder almacenar en unas variables que tengo los
> values que aparecen en el JSON. De esta forma:
>
> Con la solucion con expresiones regulares en cada iteracion tengo lo
> siguiente:
> d_value = [name,(valor del name),unit,(valor del unit),meta,(valor del
> meta),value,(valor del value)]
>
> En esa iteracion hago lo siguiente:
> if d_value[1] == "PF":
> mi_variable_PF = d_value[7]
> if d_value[1] == "Fac":
> mi_variable_Fac = d_value[7]
> .....
>
> No necesito todos los values, solo los que corresponden a unos
> determinados name.
>
> Con la solucion con expresiones regulares tengo el siguiente bug:
> Alguna veces en el json aparece "unit":"". Es decir, la clave key no
> tiene valor, por lo que no consigo
>
>
> El 3 de junio de 2014, 22:40, Flavio Danesse <fdanesse en gmail.com>
> escribió:
>
> Si quieres pasame un string de ejemplo que esté completo y dime que hacer
>> con los values y te escribo la solución.
>>
>>
>> El 3 de junio de 2014, 17:38, Flavio Danesse <fdanesse en gmail.com>
>> escribió:
>>
>> Lo que hago es tomar el string que tienes y guardarlo en un archivo como
>>> texto plano pero luego lo cargo utilizando json con lo cual obtengo un
>>> diccionario python. Para obtener las keys y values del diccionario solo
>>> tienes que hacer diccionario.keys() y diccionario.values() o puedes hacer
>>> también diccionario.items() lo cual te da la pareja key:value.
>>>
>>> En todos los casos obtendrás lista de keys, values o items.
>>>
>>> Ahora bien, el primer obstáculo está salvado, que era pasar el string a
>>> un diccionario donde tienes parejas key-value.
>>>
>>> El segundo obstaculo es hacer recursividad dentro del diccionario para
>>> seguir hacia adentro de la estructura obteniendo los diccionarios internos.
>>> No es tan complicado, puedes comenzar con algo como:
>>>
>>> for key in diccionario.keys():
>>> valor = diccionario[key]
>>> . . . lo que quieras con el key y lo que quieras con value aca
>>> importa que tipo de dato es el value, porque por lo que veo tienes listas,
>>> diccionarios, string, etc, utiliza type(valor) para operar sobre ellos
>>> según su tipo.
>>>
>>>
>>>
>>>
>>> El 3 de junio de 2014, 17:13, Miguel Angel Rodriguez <marodal en gmail.com>
>>> escribió:
>>>
>>> No entiendo que haces con archivo...
>>>>
>>>> Nunca he programado con json en python.
>>>>
>>>> ¿Como seria a partir de lo que indicas el parseo de los datos? Es
>>>> decir, ¿Como seria el bucle que me iria dando el name y el value?
>>>>
>>>>
>>>>
>>>>
>>>> 2014-06-03 22:08 GMT+02:00 Flavio Danesse <fdanesse en gmail.com>:
>>>>
>>>> Voto por lo correcto que sería así:
>>>>>
>>>>> import os
>>>>> import json
>>>>> import codecs
>>>>>
>>>>> text =
>>>>> '{"format":"JSON","result":{"devices":[{"key":"SCGDE1BA:180340320", etc
>>>>> . . .
>>>>>
>>>>> path = "/tmp/x.json"
>>>>>
>>>>> archivo = open(path, "w")
>>>>> archivo.write(text)
>>>>> archivo.close()
>>>>>
>>>>> archivo = codecs.open(path, "r", "utf-8")
>>>>> diccionario = json.JSONDecoder("utf-8").decode(archivo.read())
>>>>>
>>>>>
>>>>> El 3 de junio de 2014, 8:03, <gustavo en nodo50.org> escribió:
>>>>>
>>>>> ejecutando esto:
>>>>>>
>>>>>> #!/usr/bin/python3
>>>>>> import re
>>>>>> value_str =
>>>>>>
>>>>>> '{"format":"JSON","result":{"devices":[{"key":"SCGDE1BA:180340320","channels":[{"name":"PF","unit":"","meta":"PF","value":"1.000"},{"name":"P-WSpt","unit":"kW","meta":"P-WSpt","value":"935"},{"name":"Vac","unit":"V","meta":"Vac","value":"217.5"},{"name":"Iac","unit":"A","meta":"Iac","value":"513.8"},{"name":"Pac","unit":"kW","meta":"Pac","value":"335.2"},{"name":"Qac","unit":"kVAr","meta":"Qac","value":"-1.0"},{"name":"Sac","unit":"kVA","meta":"Sac","value":"335.1"},{"name":"Fac","unit":"Hz","meta":"Fac","value":"49.950"},{"name":"ErrNoFirst","unit":"","meta":"ErrNoFirst","value":"0"},{"name":"P-WModFailStt","unit":"","meta":"P-WModFailStt","value":"Off"},{"name":"P-WModStt","unit":"","meta":"P-WModStt","value":"Off"},{"name":"Dsc","unit":"","meta":"Dsc","value":"---"},{"name":"Firmware-9","unit":"","meta":"Firmware-9","value":""},{"name":"Cntry","unit":"","meta":"Cntry","value":"DE1"}
>>>>>>
>>>>>> ,{"name":"Type","unit":"","meta":"Type","value":"SCG"},{"name":"Mode","unit":"","meta":"Mode","value":"Operation"},{"name":"Error","unit":"","meta":"Error","value":"---"}]}]},"version":"1.0"'
>>>>>>
>>>>>> for channel_str in
>>>>>> re.findall("\"name\":\"[A-Za-z0-9\-.]+\"",value_str):
>>>>>> for channel_str1 in
>>>>>> re.findall("\"value\":\"[A-Za-z0-9\-.]+\"",value_str):
>>>>>> print ( channel_str + ";" + channel_str1 )
>>>>>>
>>>>>> me da esto:
>>>>>>
>>>>>> "name":"Cntry";"value":"335.2"
>>>>>> "name":"Cntry";"value":"-1.0"
>>>>>> "name":"Cntry";"value":"335.1"
>>>>>> "name":"Cntry";"value":"49.950"
>>>>>> "name":"Cntry";"value":"0"
>>>>>> "name":"Cntry";"value":"Off"
>>>>>> "name":"Cntry";"value":"Off"
>>>>>> "name":"Cntry";"value":"---"
>>>>>> "name":"Cntry";"value":"DE1"
>>>>>> "name":"Cntry";"value":"SCG"
>>>>>> "name":"Cntry";"value":"Operation"
>>>>>> "name":"Cntry";"value":"---"
>>>>>> "name":"Type";"value":"1.000"
>>>>>> "name":"Type";"value":"935"
>>>>>> "name":"Type";"value":"217.5"
>>>>>> "name":"Type";"value":"513.8"
>>>>>> "name":"Type";"value":"335.2"
>>>>>> "name":"Type";"value":"-1.0"
>>>>>> "name":"Type";"value":"335.1"
>>>>>> "name":"Type";"value":"49.950"
>>>>>>
>>>>>>
>>>>>> te vale?
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> > Hola a todos,
>>>>>> >
>>>>>> > Estoy intentando parsear con Python una gran cadena que recibo en un
>>>>>> > software de comunicaciones que estoy programando.
>>>>>> >
>>>>>> > La cadena que yo recibo es la siguiente:
>>>>>> >
>>>>>> > value_str =
>>>>>> >
>>>>>> {"format":"JSON","result":{"devices":[{"key":"SCGDE1BA:180340320","channels":[{"name":"PF","unit":"","meta":"PF","value":"1.000"},{"name":"P-WSpt","unit":"kW","meta":"P-WSpt","value":"935"},
>>>>>> >
>>>>>> >
>>>>>> {"name":"Vac","unit":"V","meta":"Vac","value":"217.5"},{"name":"Iac","unit":"A","meta":"Iac","value":"513.8"},{"name":"Pac","unit":"kW","meta":"Pac","value":"335.2"},{"name":"Qac","unit":"kV
>>>>>> >
>>>>>> >
>>>>>> Ar","meta":"Qac","value":"-1.0"},{"name":"Sac","unit":"kVA","meta":"Sac","value":"335.1"},{"name":"Fac","unit":"Hz","meta":"Fac","value":"49.950"},{"name":"ErrNoFirst","unit":"","meta":"ErrNoFirst","value":"0"},{"
>>>>>> >
>>>>>> >
>>>>>> name":"P-WModFailStt","unit":"","meta":"P-WModFailStt","value":"Off"},{"name":"P-WModStt","unit":"","meta":"P-WModStt","value":"Off"},{"name":"Dsc","unit":"","meta":"Dsc","value":"---"},{"name":"Firmware-9","unit":"","meta":"Firmware-9","value":"
>>>>>> > "},{"name":"Cntry","unit":"","meta":"Cntry","value":"DE1"}
>>>>>> >
>>>>>> ,{"name":"Type","unit":"","meta":"Type","value":"SCG"},{"name":"Mode","unit":"","meta":"Mode","value":"Operation"},{"name":"Error","unit":"","meta":"Error","value":"---"}]}]},"version":"1.0"
>>>>>> >
>>>>>> >
>>>>>> > Yo solo quiero quedarme con los name y value existente.
>>>>>> >
>>>>>> > LA forma en la que lo estoy intentando es la siguiente:
>>>>>> >
>>>>>> > for channel_str in re.findall("\"name\":\"[A-Za-z0-9\-.
>>>>>> > ]+\",\"value\":\"[A-Za-z0-9\-. ]*\"",value_str):
>>>>>> > d_value = re.findall("[A-Za-z0-9.\-]+",channel_str)
>>>>>> >
>>>>>> > Pero de esta forma no entra en el for.
>>>>>> >
>>>>>> > ¿Alguien me puede ayudar?
>>>>>> >
>>>>>> > Gracias y un saludo
>>>>>> >
>>>>>> >
>>>>>> >
>>>>>> >
>>>>>> >
>>>>>> >
>>>>>> > --
>>>>>> > Miguel Ángel Rodríguez de Alba
>>>>>> > 678304435
>>>>>> > marodal en gmail.com
>>>>>> > _______________________________________________
>>>>>> > Python-es mailing list
>>>>>> > Python-es en python.org
>>>>>> > https://mail.python.org/mailman/listinfo/python-es
>>>>>> > FAQ: http://python-es-faq.wikidot.com/
>>>>>> >
>>>>>>
>>>>>>
>>>>>> _______________________________________________
>>>>>> Python-es mailing list
>>>>>> Python-es en python.org
>>>>>> https://mail.python.org/mailman/listinfo/python-es
>>>>>> FAQ: http://python-es-faq.wikidot.com/
>>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> Python-es mailing list
>>>>> Python-es en python.org
>>>>> https://mail.python.org/mailman/listinfo/python-es
>>>>> FAQ: http://python-es-faq.wikidot.com/
>>>>>
>>>>>
>>>>
>>>>
>>>> --
>>>> Miguel Ángel Rodríguez de Alba
>>>> 678304435
>>>> marodal en gmail.com
>>>>
>>>> _______________________________________________
>>>> Python-es mailing list
>>>> Python-es en python.org
>>>> https://mail.python.org/mailman/listinfo/python-es
>>>> FAQ: http://python-es-faq.wikidot.com/
>>>>
>>>>
>>>
>>
>> _______________________________________________
>> Python-es mailing list
>> Python-es en python.org
>> https://mail.python.org/mailman/listinfo/python-es
>> FAQ: http://python-es-faq.wikidot.com/
>>
>>
>
>
> --
> Miguel Ángel Rodríguez de Alba
> 678304435
> marodal en gmail.com
>
--
Miguel Ángel Rodríguez de Alba
678304435
marodal en gmail.com
------------ próxima parte ------------
Se ha borrado un adjunto en formato HTML...
URL: <http://mail.python.org/pipermail/python-es/attachments/20140603/9b435a84/attachment.html>
Más información sobre la lista de distribución Python-es