add read me

venv/lib/python3.12/site-packages/sympy/plotting/backends/textbackend/__init__.py

@@ -0,0 +1,3 @@
+from sympy.plotting.backends.textbackend.text import TextBackend
+
+__all__ = ["TextBackend"]

venv/lib/python3.12/site-packages/sympy/plotting/backends/textbackend/text.py

@@ -0,0 +1,24 @@
+import sympy.plotting.backends.base_backend as base_backend
+from sympy.plotting.series import LineOver1DRangeSeries
+from sympy.plotting.textplot import textplot
+
+
+class TextBackend(base_backend.Plot):
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+    def show(self):
+        if not base_backend._show:
+            return
+        if len(self._series) != 1:
+            raise ValueError(
+                'The TextBackend supports only one graph per Plot.')
+        elif not isinstance(self._series[0], LineOver1DRangeSeries):
+            raise ValueError(
+                'The TextBackend supports only expressions over a 1D range')
+        else:
+            ser = self._series[0]
+            textplot(ser.expr, ser.start, ser.end)
+
+    def close(self):
+        pass