ex35

ex35.py

@@ -0,0 +1,7 @@
+import reader
+import stock
+import tableformat
+
+portfolio = reader.read_csv_as_instances("Data/portfolio.csv", stock.Stock)
+formatter = tableformat.create_formatter("text")
+tableformat.print_table(portfolio, ["name", "shares", "price"], formatter)

tableformat.py

@@ -1,5 +1,62 @@
-def print_table(objects, attributes):
+class TableFormatter:
-    print(*("{: >10}".format(attr) for attr in attributes))
+    def headings(self, headers):
-    print(*("{:->10}".format("") for _ in attributes))
+        raise NotImplementedError()
-    for obj in objects:
+
-        print(*("{: >10}".format(getattr(obj, attr, "")) for attr in attributes))
+    def row(self, rowdata):
+        raise NotImplementedError()
+
+
+class TextTableFormatter:
+    def _printer(self, data):
+        print(*("{: >10}".format(value) for value in data))
+
+    def headings(self, headers):
+        self._printer(headers)
+        print(*("{:->10}".format("") for _ in headers))
+
+    def row(self, rowdata):
+        self._printer(rowdata)
+
+
+class CSVTableFormatter:
+    def _printer(self, data):
+        print(",".join(str(value) for value in data))
+
+    def headings(self, headers):
+        return self._printer(headers)
+
+    def row(self, rowdata):
+        return self._printer(rowdata)
+
+
+class HTMLTableFormatter:
+    def _cell(self, value, tag):
+        return f"<{tag}>{value}</{tag}>"
+
+    def _printer(self, data, tag):
+        line = f"<tr>{' '.join(self._cell(str(value), tag) for value in data)}</tr>"
+        print(line)
+
+    def headings(self, headers):
+        return self._printer(headers, "th")
+
+    def row(self, rowdata):
+        return self._printer(rowdata, "td")
+
+
+def create_formatter(name):
+    formatters = {
+        "text": TextTableFormatter,
+        "csv": CSVTableFormatter,
+        "html": HTMLTableFormatter,
+    }
+    formatter = formatters.get(name, None)
+    if not name:
+        raise ValueError(f'formatter named "{name}" not implemented')
+    return formatter()
+
+
+def print_table(records, fields, formatter):
+    formatter.headings(fields)
+    for record in records:
+        formatter.row([getattr(record, fieldname) for fieldname in fields])