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posthog/ee/clickhouse/queries/funnels/funnel_trends.py
Rick Marron 0464a51d7d
Fix funnel order on the person modal for funnel trends (#8210)
* fix funnel order on funnel trend persons

* add utils test

* update test for cache update

* remove dupe import
2022-01-25 09:20:42 -08:00

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from datetime import date, datetime
from itertools import groupby
from typing import List, Optional, Tuple, Union, cast
from dateutil.relativedelta import relativedelta
from ee.clickhouse.queries.funnels.base import ClickhouseFunnelBase
from ee.clickhouse.queries.funnels.utils import get_funnel_order_class
from ee.clickhouse.queries.util import (
format_ch_timestamp,
get_earliest_timestamp,
get_interval_func_ch,
get_trunc_func_ch,
)
from posthog.models.cohort import Cohort
from posthog.models.filters.filter import Filter
from posthog.models.team import Team
TIMESTAMP_FORMAT = "%Y-%m-%d %H:%M:%S"
HUMAN_READABLE_TIMESTAMP_FORMAT = "%-d-%b-%Y"
class ClickhouseFunnelTrends(ClickhouseFunnelBase):
"""
## Funnel trends assumptions
Funnel trends are a graph of conversion over time meaning a Y ({conversion_rate}) for each X ({entrance_period}).
### What is {entrance_period}?
A funnel is considered entered by a user when they have performed its first step.
When that happens, we consider that an entrance of funnel.
Now, our time series is based on a sequence of {entrance_period}s, each starting at {entrance_period_start}
and ending _right before the next_ {entrance_period_start}. A person is then counted at most once in each
{entrance_period}.
### What is {conversion_rate}?
Each time a funnel is entered by a person, they have exactly {funnel_window_interval} {funnel_window_interval_unit} to go
through the funnel's steps. Later events are just not taken into account.
For {conversion_rate}, we need to know reference steps: {from_step} and {to_step}.
By default they are respectively the first and the last steps of the funnel.
Then for each {entrance_period} we calculate {reached_from_step_count} the number of persons
who entered the funnel and reached step {from_step} (along with all the steps leading up to it, if there any).
Similarly we calculate {reached_to_step_count}, which is the number of persons from {reached_from_step_count}
who also reached step {to_step} (along with all the steps leading up to it, including of course step {from_step}).
{conversion_rate} is simply {reached_to_step_count} divided by {reached_from_step_count},
multiplied by 100 to be a percentage.
If no people have reached step {from_step} in the period, {conversion_rate} is zero.
"""
def __init__(self, filter: Filter, team: Team) -> None:
super().__init__(filter, team)
self.funnel_order = get_funnel_order_class(filter)(filter, team)
def _exec_query(self):
return self._summarize_data(super()._exec_query())
def get_step_counts_without_aggregation_query(
self, *, specific_entrance_period_start: Optional[datetime] = None
) -> str:
steps_per_person_query = self.funnel_order.get_step_counts_without_aggregation_query()
trunc_func = get_trunc_func_ch(self._filter.interval)
# This is used by funnel trends when we only need data for one period, e.g. person per data point
if specific_entrance_period_start:
self.params["entrance_period_start"] = specific_entrance_period_start.strftime(TIMESTAMP_FORMAT)
breakdown_clause = self._get_breakdown_prop()
return f"""
SELECT
aggregation_target,
{trunc_func}(timestamp) AS entrance_period_start,
max(steps) AS steps_completed
{breakdown_clause}
FROM (
{steps_per_person_query}
)
{"WHERE toDateTime(entrance_period_start) = %(entrance_period_start)s" if specific_entrance_period_start else ""}
GROUP BY aggregation_target, entrance_period_start {breakdown_clause}"""
def get_query(self) -> str:
step_counts = self.get_step_counts_without_aggregation_query()
# Expects multiple rows for same person, first event time, steps taken.
self.params.update(self.funnel_order.params)
reached_from_step_count_condition, reached_to_step_count_condition, _ = self.get_steps_reached_conditions()
trunc_func = get_trunc_func_ch(self._filter.interval)
interval_func = get_interval_func_ch(self._filter.interval)
if self._filter.date_from is None:
_date_from = get_earliest_timestamp(self._team.pk)
else:
_date_from = self._filter.date_from
breakdown_clause = self._get_breakdown_prop()
formatted_date_from = format_ch_timestamp(_date_from, self._filter)
formatted_date_to = format_ch_timestamp(self._filter.date_to, self._filter)
self.params.update(
{
"formatted_date_from": formatted_date_from,
"formatted_date_to": formatted_date_to,
"interval": self._filter.interval,
}
)
query = f"""
SELECT
entrance_period_start,
reached_from_step_count,
reached_to_step_count,
if(reached_from_step_count > 0, round(reached_to_step_count / reached_from_step_count * 100, 2), 0) AS conversion_rate
{breakdown_clause}
FROM (
SELECT
entrance_period_start,
countIf({reached_from_step_count_condition}) AS reached_from_step_count,
countIf({reached_to_step_count_condition}) AS reached_to_step_count
{breakdown_clause}
FROM (
{step_counts}
) GROUP BY entrance_period_start {breakdown_clause}
) data
RIGHT OUTER JOIN (
SELECT
{trunc_func}(toDateTime(%(formatted_date_from)s) + {interval_func}(number)) AS entrance_period_start
{', breakdown_value as prop' if breakdown_clause else ''}
FROM numbers(dateDiff(%(interval)s, toDateTime(%(formatted_date_from)s), toDateTime(%(formatted_date_to)s)) + 1) AS period_offsets
{'ARRAY JOIN (%(breakdown_values)s) AS breakdown_value' if breakdown_clause else ''}
) fill
USING (entrance_period_start {breakdown_clause})
ORDER BY entrance_period_start ASC
SETTINGS allow_experimental_window_functions = 1"""
return query
def get_steps_reached_conditions(self) -> Tuple[str, str, str]:
# How many steps must have been done to count for the denominator of a funnel trends data point
from_step = self._filter.funnel_from_step or 0
# How many steps must have been done to count for the numerator of a funnel trends data point
to_step = self._filter.funnel_to_step or len(self._filter.entities) - 1
# Those who converted OR dropped off
reached_from_step_count_condition = f"steps_completed >= {from_step+1}"
# Those who converted
reached_to_step_count_condition = f"steps_completed >= {to_step+1}"
# Those who dropped off
did_not_reach_to_step_count_condition = f"{reached_from_step_count_condition} AND steps_completed < {to_step+1}"
return reached_from_step_count_condition, reached_to_step_count_condition, did_not_reach_to_step_count_condition
def _summarize_data(self, results):
breakdown_clause = self._get_breakdown_prop()
summary = []
for period_row in results:
serialized_result = {
"timestamp": period_row[0],
"reached_from_step_count": period_row[1],
"reached_to_step_count": period_row[2],
"conversion_rate": period_row[3],
"is_period_final": self._is_period_final(period_row[0]),
}
if breakdown_clause:
if isinstance(period_row[-1], str) or (
isinstance(period_row[-1], List) and all(isinstance(item, str) for item in period_row[-1])
):
serialized_result.update({"breakdown_value": (period_row[-1])})
else:
serialized_result.update({"breakdown_value": Cohort.objects.get(pk=period_row[-1]).name})
summary.append(serialized_result)
return summary
def _format_results(self, summary):
if self._filter.breakdown:
grouper = lambda row: row["breakdown_value"]
sorted_data = sorted(summary, key=grouper)
final_res = []
for key, value in groupby(sorted_data, grouper):
breakdown_res = self._format_single_summary(list(value))
final_res.append({**breakdown_res, "breakdown_value": key})
return final_res
else:
res = self._format_single_summary(summary)
return [res]
def _format_single_summary(self, summary):
count = len(summary)
data = []
days = []
labels = []
for row in summary:
timestamp: datetime = row["timestamp"]
data.append(row["conversion_rate"])
hour_min_sec = " %H:%M:%S" if self._filter.interval == "hour" else ""
days.append(timestamp.strftime(f"%Y-%m-%d{hour_min_sec}"))
labels.append(timestamp.strftime(HUMAN_READABLE_TIMESTAMP_FORMAT))
return {
"count": count,
"data": data,
"days": days,
"labels": labels,
}
def _is_period_final(self, timestamp: Union[datetime, date]):
# difference between current date and timestamp greater than window
now = datetime.utcnow().date()
intervals_to_subtract = cast(int, self._filter.funnel_window_interval) * -1
interval_unit = (
"day" if self._filter.funnel_window_interval_unit is None else self._filter.funnel_window_interval_unit
)
delta = relativedelta(**{f"{interval_unit}s": intervals_to_subtract}) # type: ignore
completed_end = now + delta
compare_timestamp = timestamp.date() if isinstance(timestamp, datetime) else timestamp
is_final = compare_timestamp <= completed_end
return is_final