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Python

# -*- coding: utf-8 -*-
from numpy import isnan, nan
from pandas import concat, Series
from pandas_ta._typing import DictLike, Int
from pandas_ta.maps import Imports
from pandas_ta.utils import (
non_zero_range,
v_bool,
v_drift,
v_offset,
v_series,
v_talib
)
def true_range(
high: Series, low: Series, close: Series,
talib: bool = None, prenan: bool = None, drift: Int = None,
offset: Int = None, **kwargs: DictLike
) -> Series:
"""True Range
An method to expand a classical range (high minus low) to include
possible gap scenarios.
Sources:
https://www.macroption.com/true-range/
Args:
high (pd.Series): Series of 'high's
low (pd.Series): Series of 'low's
close (pd.Series): Series of 'close's
talib (bool): If TA Lib is installed and talib is True, Returns
the TA Lib version. Default: True
prenan (bool): If True, behave like TA Lib with some initial nan
based on drift (typically 1). Default: False
drift (int): The shift period. Default: 1
offset (int): How many periods to offset the result. Default: 0
Kwargs:
fillna (value, optional): pd.DataFrame.fillna(value)
fill_method (value, optional): Type of fill method
Returns:
pd.Series: New feature
"""
# Validate
drift = v_drift(drift)
high = v_series(high)
low = v_series(low)
close = v_series(close)
mode_tal = v_talib(talib)
prenan = v_bool(prenan, False)
offset = v_offset(offset)
# Calculate
if Imports["talib"] and mode_tal:
from talib import TRANGE
true_range = TRANGE(high, low, close)
else:
hl_range = non_zero_range(high, low)
pc = close.shift(drift)
ranges = [hl_range, high - pc, pc - low]
true_range = concat(ranges, axis=1)
true_range = true_range.abs().max(axis=1)
if prenan:
true_range.iloc[:drift] = nan
if all(isnan(true_range)):
return # Emergency Break
# Offset
if offset != 0:
true_range = true_range.shift(offset)
# Fill
if "fillna" in kwargs:
true_range.fillna(kwargs["fillna"], inplace=True)
if "fill_method" in kwargs:
true_range.fillna(method=kwargs["fill_method"], inplace=True)
# Name and Category
true_range.name = f"TRUERANGE_{drift}"
true_range.category = "volatility"
return true_range