Added lookahead interface to ichimoku and dpo indicators

Indicators with potential data leak should handle lookahead=False kwargs

README.md

@@ -85,7 +85,7 @@ _Pandas Technical Analysis_ (**Pandas TA**) is an easy to use library that lever
 * Have the need for speed? By using the DataFrame _strategy_ method, you get **multiprocessing** for free! __Conditions permitting__.
 * Easily add _prefixes_ or _suffixes_ or _both_ to columns names. Useful for Custom Chained Strategies.
 * Example Jupyter Notebooks under the [examples](https://github.com/twopirllc/pandas-ta/tree/main/examples) directory, including how to create Custom Strategies using the new [__Strategy__ Class](https://github.com/twopirllc/pandas-ta/tree/main/examples/PandaTA_Strategy_Examples.ipynb)
-* Potential Data Leaks: **ichimoku** and **dpo**. See indicator list below for details.
+* Potential Data Leaks: **ichimoku** and **dpo**. See indicator list below for details. Set ```lookahead=False``` to disable.
 
 <br/>
 
@@ -733,7 +733,7 @@ df = df.ta.cdl_pattern(name=["doji", "inside"])
 * _Holt-Winter Moving Average_: **hwma**
 * _Ichimoku Kinkō Hyō_: **ichimoku**
     * Returns two DataFrames. For more information: ```help(ta.ichimoku)```.
-    * Drop the Chikou Span Column, the final column of the first resultant DataFrame, remove potential data leak.
+    * ```lookahead=False``` drops the Chikou Span Column to prevent potential data leak.
 * _Kaufman's Adaptive Moving Average_: **kama**
 * _Linear Regression_: **linreg**
 * _McGinley Dynamic_: **mcgd**
@@ -807,7 +807,7 @@ Use parameter: cumulative=**True** for cumulative results.
     * Formally: **linear_decay**
 * _Decreasing_: **decreasing**
 * _Detrended Price Oscillator_: **dpo**
-    * Set ```centered=False``` to remove potential data leak.
+    * Set ```lookahead=False``` to disable centering and remove potential data leak.
 * _Increasing_: **increasing**
 * _Long Run_: **long_run**
 * _Parabolic Stop and Reverse_: **psar**

pandas_ta/core.py

@@ -1196,11 +1196,11 @@ class AnalysisIndicators(BasePandasObject):
         result = kama(close=close, length=length, fast=fast, slow=slow, offset=offset, **kwargs)
         return self._post_process(result, **kwargs)
 
-    def ichimoku(self, tenkan=None, kijun=None, senkou=None, offset=None, **kwargs):
+    def ichimoku(self, tenkan=None, kijun=None, senkou=None, include_chikou=True, offset=None, **kwargs):
         high = self._get_column(kwargs.pop("high", "high"))
         low = self._get_column(kwargs.pop("low", "low"))
         close = self._get_column(kwargs.pop("close", "close"))
-        result, span = ichimoku(high=high, low=low, close=close, tenkan=tenkan, kijun=kijun, senkou=senkou, offset=offset, **kwargs)
+        result, span = ichimoku(high=high, low=low, close=close, tenkan=tenkan, kijun=kijun, senkou=senkou, include_chikou=include_chikou, offset=offset, **kwargs)
         self._add_prefix_suffix(result, **kwargs)
         self._add_prefix_suffix(span, **kwargs)
         self._append(result, **kwargs)

pandas_ta/overlap/ichimoku.py

@@ -4,7 +4,7 @@ from .midprice import midprice
 from pandas_ta.utils import get_offset, verify_series
 
 
-def ichimoku(high, low, close, tenkan=None, kijun=None, senkou=None, offset=None, **kwargs):
+def ichimoku(high, low, close, tenkan=None, kijun=None, senkou=None, include_chikou=True, offset=None, **kwargs):
     """Indicator: Ichimoku Kinkō Hyō (Ichimoku)"""
     tenkan = int(tenkan) if tenkan and tenkan > 0 else 9
     kijun = int(kijun) if kijun and kijun > 0 else 26
@@ -14,6 +14,8 @@ def ichimoku(high, low, close, tenkan=None, kijun=None, senkou=None, offset=None
     low = verify_series(low, _length)
     close = verify_series(close, _length)
     offset = get_offset(offset)
+    if not kwargs.get("lookahead", True):
+        include_chikou = False
 
     if high is None or low is None or close is None: return None, None
 
@@ -65,8 +67,10 @@ def ichimoku(high, low, close, tenkan=None, kijun=None, senkou=None, offset=None
         span_b.name: span_b,
         tenkan_sen.name: tenkan_sen,
         kijun_sen.name: kijun_sen,
-        chikou_span.name: chikou_span,
     }
+    if include_chikou:
+        data[chikou_span.name] = chikou_span
+
     ichimokudf = DataFrame(data)
     ichimokudf.name = f"ICHIMOKU_{tenkan}_{kijun}_{senkou}"
     ichimokudf.category = "overlap"
@@ -121,6 +125,7 @@ Args:
     tenkan (int): Tenkan period. Default: 9
     kijun (int): Kijun period. Default: 26
     senkou (int): Senkou period. Default: 52
+    include_chikou (bool): Whether to include chikou component. Default: True
     offset (int): How many periods to offset the result. Default: 0
 
 Kwargs:

pandas_ta/trend/dpo.py

@@ -9,6 +9,8 @@ def dpo(close, length=None, centered=True, offset=None, **kwargs):
     length = int(length) if length and length > 0 else 20
     close = verify_series(close, length)
     offset = get_offset(offset)
+    if not kwargs.get("lookahead", True):
+        centered = False
 
     if close is None: return