From 2af0ccfab7800bcffd082c9d14751afa4e67b76d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tolga=20G=C3=B6=C4=9Febakan?=
 <39372186+tlgoa@users.noreply.github.com>
Date: Fri, 4 Oct 2024 18:03:31 +0300
Subject: [PATCH 1/2] Create relative_strength_index.py

---
 financial/relative_strength_index.py | 73 ++++++++++++++++++++++++++++
 1 file changed, 73 insertions(+)
 create mode 100644 financial/relative_strength_index.py

diff --git a/financial/relative_strength_index.py b/financial/relative_strength_index.py
new file mode 100644
index 000000000000..dff6c2995a05
--- /dev/null
+++ b/financial/relative_strength_index.py
@@ -0,0 +1,73 @@
+def calculate_rsi(prices: list[float], period: int = 14) -> list[float]:
+    """
+    Calculate the Relative Strength Index (RSI) for a given list of prices.
+
+    RSI is a momentum oscillator that measures the speed and change of price movements.
+    It is typically used to identify overbought or oversold conditions in a market.
+
+    Args:
+        prices (list[float]): A list of prices for a financial asset.
+        period (int): The number of periods to use in the calculation (default is 14).
+
+    Returns:
+        list[float]: A list of RSI values corresponding to the input price data.
+
+    Example:
+        >>> calculate_rsi([44.0, 44.15, 44.09, 44.20, 44.30, 44.25, 44.40], 14)
+        [100.0, 100.0, 100.0, 100.0, 100.0, 100.0]
+
+    Reference:
+        https://en.wikipedia.org/wiki/Relative_strength_index
+    """
+    # Validate that there are enough prices to calculate RSI
+    if len(prices) < period:
+        raise ValueError("Not enough price data to calculate RSI.")
+
+    gains = []
+    losses = []
+
+    # Calculate price changes between consecutive days
+    for i in range(1, len(prices)):
+        delta = prices[i] - prices[i - 1]
+        gains.append(max(0, delta))
+        losses.append(max(0, -delta))
+
+    # Initial averages for gain and loss
+    avg_gain = float(sum(gains[:period]) / period)
+    avg_loss = float(sum(losses[:period]) / period)
+
+    # Initialize RSI list and first RSI value
+    rsi_values: list[float] = []
+
+    if avg_loss == 0:
+        rsi = 100.0
+    else:
+        rs = avg_gain / avg_loss
+        rsi = 100.0 - (100.0 / (1.0 + rs))
+
+    rsi_values.append(rsi)
+
+    # Calculate subsequent RSI values
+    for i in range(period, len(prices)):
+        delta = prices[i] - prices[i - 1]
+        gain = max(0, delta)
+        loss = max(0, -delta)
+
+        avg_gain = (avg_gain * (period - 1) + gain) / period
+        avg_loss = (avg_loss * (period - 1) + loss) / period
+
+        if avg_loss == 0:
+            rsi = 100.0
+        else:
+            rs = avg_gain / avg_loss
+            rsi = 100.0 - (100.0 / (1.0 + rs))
+
+        rsi_values.append(rsi)
+
+    return rsi_values
+
+
+if __name__ == "__main__":
+    prices = [44.0, 44.15, 44.09, 44.20, 44.30, 44.25, 44.40, 44.35, 44.50, 44.60, 44.55, 44.75, 44.80, 44.70, 44.85]
+    rsi = calculate_rsi(prices, 14)
+    print("RSI Values:", rsi)

From c4851d62b5b148d17762538ff465bcc0531e3af2 Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Fri, 4 Oct 2024 15:05:08 +0000
Subject: [PATCH 2/2] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 financial/relative_strength_index.py | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/financial/relative_strength_index.py b/financial/relative_strength_index.py
index dff6c2995a05..e57d36e7864d 100644
--- a/financial/relative_strength_index.py
+++ b/financial/relative_strength_index.py
@@ -68,6 +68,22 @@ def calculate_rsi(prices: list[float], period: int = 14) -> list[float]:
 
 
 if __name__ == "__main__":
-    prices = [44.0, 44.15, 44.09, 44.20, 44.30, 44.25, 44.40, 44.35, 44.50, 44.60, 44.55, 44.75, 44.80, 44.70, 44.85]
+    prices = [
+        44.0,
+        44.15,
+        44.09,
+        44.20,
+        44.30,
+        44.25,
+        44.40,
+        44.35,
+        44.50,
+        44.60,
+        44.55,
+        44.75,
+        44.80,
+        44.70,
+        44.85,
+    ]
     rsi = calculate_rsi(prices, 14)
     print("RSI Values:", rsi)