initial attempt at esc/pos generation

print_tape.py

@@ -0,0 +1,64 @@
+#!/usr/bin/env python3
+"""Generate ESC/POS ticker tape output from trade CSV data.
+
+Reads a CSV of trades (timestamp, symbol, lots, price) and generates
+ESC/POS commands with 90° rotated text to emulate an old stock ticker tape.
+
+When the receipt paper is turned sideways:
+  - Symbol appears at the top of the tape
+  - Price (and lot count) appears at the bottom
+"""
+
+import csv
+import sys
+
+from escpos.printer import Dummy
+
+# TM-T88V: 42 columns at Font A on 80mm paper
+LINE_WIDTH = 42
+
+
+def format_trade(symbol, lots, price):
+    """Format a trade line for the ticker tape.
+
+    Symbol is placed at the start of the line, price info at the end.
+    With 90° rotation, start-of-line = top of tape, end-of-line = bottom.
+    """
+    if lots > 1:
+        price_str = f"{lots}s{price:.2f}"
+    else:
+        price_str = f"{price:.2f}"
+
+    padding = LINE_WIDTH - len(symbol) - len(price_str)
+    if padding < 1:
+        padding = 1
+    return symbol + " " * padding + price_str
+
+
+def main():
+    csv_file = sys.argv[1] if len(sys.argv) > 1 else "trades_sample_sorted.csv"
+    output_file = sys.argv[2] if len(sys.argv) > 2 else "ticker_tape.bin"
+
+    p = Dummy(profile="TM-T88V")
+    p.hw("INIT")
+    # ESC V 1: 90° clockwise character rotation (not exposed by python-escpos)
+    p._raw(b"\x1b\x56\x01")
+
+    with open(csv_file) as f:
+        reader = csv.reader(f)
+        for row in reader:
+            _timestamp, symbol, lots_str, price_str = row
+            lots = int(lots_str)
+            price = float(price_str)
+            line = format_trade(symbol, lots, price)
+            p.text(line + "\n")
+
+    p.cut()
+
+    with open(output_file, "wb") as f:
+        f.write(p.output)
+    print(f"Wrote {len(p.output)} bytes to {output_file}", file=sys.stderr)
+
+
+if __name__ == "__main__":
+    main()