[PATCH] tbot_contrib/utils.py: convert a string into a dictionary via a pattern
Heiko Schocher
hs at denx.de
Thu May 7 14:25:30 CEST 2020
Hello Harald,
Am 05.05.2020 um 17:02 schrieb Harald Seiler:
> Hello Heiko,
>
> On Mon, 2020-04-20 at 15:51 +0200, Heiko Schocher wrote:
>> introduce function string_to_dict(), which converts
>> a string into dictionary via a pattern.
>
> Can you quickly explain where this helper is useful to you? IMO the name
> string_to_dict() doesn't really hint at what it does. If I can see this
> correctly, this is kind of a reverse string formatting. So maybe
> match_format(), parse_format(), or unformat() would be more appropriate?
I used if for example to parse a output line of the latency
command:
output lines are from the follwoing format:
# RTT| 00:00:01 (periodic user-mode task, 1000 us period, priority 99)
# RTH|----lat min|----lat avg|----lat max|-overrun|---msw|---lat best|--lat worst
# RTD| 11.458| 16.702| 39.250| 0| 0| 11.458| 39.250
so if a line contains RTD I used the format:
rtd_format = 'RTD\|{min}\|{avg}\|{max}\|{overrun}\|{msw}\|{best}\|{worst}'
and did:
for l in ret:
if 'RTD' in l["out"]:
rtd_dict = string_to_dict(l["out"], rtd_format)
Ok, we can rename it to "parse_format" ?
But may there is some easier trick with python 3 ?
>
>> Signed-off-by: Heiko Schocher <hs at denx.de>
>> ---
>>
>> tbot_contrib/utils.py | 25 +++++++++++++++++++++++++
>> 1 file changed, 25 insertions(+)
>>
>> diff --git a/tbot_contrib/utils.py b/tbot_contrib/utils.py
>> index 8073f89..1afb65b 100644
>> --- a/tbot_contrib/utils.py
>> +++ b/tbot_contrib/utils.py
>> @@ -15,6 +15,7 @@
>> # along with this program. If not, see <https://www.gnu.org/licenses/>;;;.
>>
>> from tbot.machine import linux
>> +import re
>>
>>
>> def check_systemd_services_running(lnx: linux.LinuxShell, services: list) -> None:
>> @@ -29,3 +30,27 @@ def check_systemd_services_running(lnx: linux.LinuxShell, services: list) -> Non
>> ret = lnx.exec("systemctl", "status", s, "--no-pager")
>> if ret[0] != 0:
>> lnx.test("sudo", "systemctl", "start", s)
>> +
>> +
>> +def string_to_dict(string: str, pattern: str) -> dict:
>
> Annotation for the return type needs to be typing.Dict[str, str].
>
> Also, to keep consistent with the rest of Python (e.g. the `re` module),
> the arguments should be switched so that pattern comes first.
Ok, can clean this up...
>> + """
>> + convert a string into a dictionary via a pattern
>> +
>> + example pattern:
>> + 'hello, my name is {name} and I am a {age} year old {what}'
>> +
>> + string:
>> + 'hello, my name is dan and I am a 33 year old developer'
>> +
>> + returned dict:
>> + {'age': '33', 'name': 'dan', 'what': 'developer'}
>> + from:
>> + https://stackoverflow.com/questions/11844986/convert-or-unformat-a-string-to-variables-like-format-but-in-reverse-in-p
>> + """
>> + regex = re.sub(r"{(.+?)}", r"(?P<_\1>.+)", pattern)
>
> The match-pattern used here, `(?P<_group>.+)` matches greedy. This means
> for your above example that the following string
>
> hello, my name is dan and I am a 33 year old developer and I am a 33 year old developer
>
> will yield
>
> {'name': 'dan and I am a 33 year old developer', 'age': '33',
> 'what': 'developer'}
>
> Not sure if this is a problem though. It could be changed by using
> `(?P<_group>.+?)` instead if non-greedy behavior is more desirable.
Yes, I change this.
Thanks!
bye,
Heiko
>
>> + match = re.search(regex, string)
>> + assert match is not None, f"The pattern {regex!r} was not found!"
>> + values = list(match.groups())
>> + keys = re.findall(r"{(.+?)}", pattern)
>> + _dict = dict(zip(keys, values))
>> + return _dict
--
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