[Python] What is the Indie's equivalent to Pinescript's StDev algorithm?

I'm trying to create a simple volatility indicator in Indie but keep getting an error when trying to import the standard deviation algorithm.

I'm getting this error:

Error: 3:39 package indie.algorithms does not contain symbol Stdev
​

Here's my code:

# indie:lang_version = 5
from indie import indicator, param, plot, color, source, MainContext
from indie.algorithms import Stdev, Ema

@indicator("StdDev Volatility Indicator")
@param.int("length", default=20, min=1, title="StdDev Period")
@param.int("smooth_length", default=10, min=1, title="Smoothing Period")
@param.float("threshold_high", default=2.0, title="High Volatility Threshold")
@param.float("threshold_medium", default=1.0, title="Medium Volatility Threshold")
@param.source("source", default=source.CLOSE, title="Price Source")
@plot.line(title="StdDev", color=color.BLUE)
@plot.line(title="Smoothed StdDev", color=color.RED)
@plot.line(title="High Threshold", color=color.RED(0.5))
@plot.line(title="Medium Threshold", color=color.YELLOW(0.5))
class Main(MainContext):
def calc(self, length, smooth_length, threshold_high, threshold_medium, source):
stddev = Stdev.new(source, length)

smoothed_stddev = Ema.new(stddev, smooth_length)

avg_stddev = Ema.new(stddev, length * 3)[0]

high_threshold = avg_stddev * threshold_high
medium_threshold = avg_stddev * threshold_medium

return (
stddev[0], # Raw standard deviation
smoothed_stddev[0], # Smoothed standard deviation
high_threshold, # High volatility threshold line
medium_threshold # Medium volatility threshold line
)


Has anyone encountered this before? Is there a different way to calculate standard deviation in Indie?

I know in PineScript I could just use ta.stdev() but I'm not sure what the equivalent is here.

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