flux-query-builder 1.0.0

A python querybuilder for the Flux query language

Flux Query Builder

Version: 1.0.0

A python querybuilder for the flux query language used by InfluxDB

Getting Started

Installation

$ pip install flux-query-builder

Building Queries

from flux_query_builder import FluxQuery
from flux_query_builder.utility import S
import flux_query_builder.functions as fn
   
q = (
   FluxQuery() 
   | fn.From(bucket=S("bucket-name")) 
   | fn.Range(start=S("-1d"))
   | fn.AggregateWindow(every=S("30m"),fn=fn.Mean)
)

print(q.get_query())

Expected Output:

from(bucket:"bucket-name")
|> range(start: "-1d")
|> aggregateWindow(every: "30m", fn: mean)

Creating your custom Functions

It is sometimes usefull to create and save a custom function for later use

For most use cases the InlineFn class is sufficent if you want to do something more custom you can inherit the FluxQueryFunction class.

from flux_query_builder.functions.base import FluxQueryFunction
from flux_query_builder.functions import InlineFn

class MeasurementFilter(FluxQueryFunction):

    name = "measurementFilter"
    package=None

    def __init__(self, measurement ):
            super().__init__(measurement=measurement)

    def __str__(self) -> str:
        return f"(r) => r._measurement == \"{self.params.get('measurement')}\")"

Fluid API

The FluxQuery class exposes all functions as it's own methods via a metaclass. Unfortunetly Intellisense is not aware of the methods but if you prefer, instead of using the pipe operator, you can use the Fluid API

Some functions in the flux langauge are python keywords because of this they are suffixed with a _

The query will still throw if the required parameters are not given!

Example:

q = (
	FluxQuery()
	.from_(bucket="bucket", start=S("-30m"))
	.filter(fn="(r) => r._measurement = 'meas'")
	.count()
)

Reference

FluxQuery

The querybuilder class. FluxQueries are immutable every operation like piping a new function with | or even adding an import creates a clone of the class

The S Utility Class

Some times you want to add parameters to functions you pipe and want them to be strings. In that case the S class is a wrapper to add qoutes to the string

Example:

from flux_query_builder import FluxQuery
from flux_query_builder.utility import S
import flux_query_builder.functions as fn

q = FluxQuery()

q = (
	q 
	| fn.Filter(fn="(r) => r._measurement = 'meas'")
	| fn.AggregateWindow(every=S("30m"),fn=fn.Mean)
)

Expected Output:

from(bucket:"bucket-name")
|> range(start: "-1d")
|> aggregateWindow(every: "30m", fn: mean)

In this case the fn argument will be taken as is and the S("30m") will be in quoutes.

The rational behind this is that there still needs to be a way to add non string values

InlineFn

A Utility class for creating inline functions like those in the filter function

Example:

from flux_query_builder.functions import InlineFn
from flux_query_builder import FluxQuery
from flux_query_builder.utility import S
# Create a function that filters out all measurements that are not "meas"
meas_filter = InlineFn("r", "r._measurement == 'meas'")
print(meas_filter)

q = FluxQuery(bucket_name="bucket-name", start=S("-1d")) | fn.Filter(fn=meas_filter)

print(q.get_query())

Expected Output:

(r) => r._measurement == 'meas'

from(bucket:"bucket-name", start: "-1d")
|> filter(fn: (r) => r._measurement == 'meas')

FluxTime

Flux time is a utlility class to deal with flux durations and dates and pythons datetimes and timedeltas

Example:

from flux_query_builder.utility import FluxTime

# Create a flux duration
duration = FluxTime(duration="1d")
print(duration)


# Create a flux duration from a timedelta
duration = FluxTime(duration=timedelta(days=1))
print(duration)

# Create a flux date from a datetime
date = FluxTime(date=datetime(2020,1,1))
print(date)

Expected Output:

1d
1d
2020-01-01T00:00:00Z

FilterBuilder

The FilterBuilder makes it easy building filters for your query by generating a InlineFunction that respects all the given conditions

Example:

from flux_query_builder import FluxQuery
from flux_query_builder.utility import S
from flux_query_builder.functions import FilterBuilder
import flux_query_builder.functions as fn

q = FluxQuery(bucket_name="bucket-name", start=S("-1d"))

# Create a filter that filters out all measurements that are not "meas" and all fields that are not "field"
build_filter = FilterBuilder().measurement("meas").field("field").build()

q = q | fn.Filter(fn=build_filter)

Expected Output:

from(bucket:"bucket-name", start: "-1d")
|> filter(fn: (r) => r._measurement == 'meas' and r._field == 'field')