From 69f3233d905b0a9af797054d4dbf87c544fc7d58 Mon Sep 17 00:00:00 2001
From: Ilja Heitlager <iheitlager@schubergphilis.com>
Date: Sun, 19 Nov 2023 18:37:59 +0100
Subject: [PATCH] adding robust sudoku reader (#29)

---
 src/sudoku/reader.py | 33 +++++++++++++++++++++++++++++
 tests/test_reader.py | 50 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 83 insertions(+)
 create mode 100644 src/sudoku/reader.py
 create mode 100644 tests/test_reader.py

diff --git a/src/sudoku/reader.py b/src/sudoku/reader.py
new file mode 100644
index 0000000..0ae4a5a
--- /dev/null
+++ b/src/sudoku/reader.py
@@ -0,0 +1,33 @@
+def read_matrix(filename):
+    """Read a matrix from a filename.
+    
+    Note: wraps generic get_matrix method.
+    """
+
+    with open(filename, "r") as f:
+        content = f.readlines()
+    return get_matrix(content)
+
+
+def get_matrix(content):
+    """Return a list of lists containing the content of text.
+
+    Note: each line of the text corresponds to a list. Each item in
+    the list is from splitting the line of text by the delimiter ' ' or ','.
+    Empty values are either 0 or . This is a fairly robust parser.
+    """
+
+    if type(content) == str: # split textblob into list of lines
+        content = content.splitlines()
+
+    lines = []
+    for line in content:
+        new_line = line.strip()    # Strip any leading or trailing whitespace
+        new_line = new_line.replace(".", "0") # dots are zero's
+        new_line = new_line.replace(",", "") # comma's are seperators
+        new_line = new_line.replace(" ", "") # spaces are seperators
+        if new_line:
+            new_line = [int(x) for x in new_line]
+            lines.append(new_line)
+
+    return lines
diff --git a/tests/test_reader.py b/tests/test_reader.py
new file mode 100644
index 0000000..6684309
--- /dev/null
+++ b/tests/test_reader.py
@@ -0,0 +1,50 @@
+from sudoku import reader
+
+
+example1 = """.......92
+...1...4.
+9..24...7
+8..7..15.
+65.9.1.78
+.74..8..6
+3...95..1
+.8...6...
+79.......
+"""
+
+example1_alt = """. . . .. ..92
+...1...4.
+9..2400.7
+
+8..7..15.
+
+6,5,.,9,.,1,.,7,8
+.74..,8,.,.,6
+
+
+3...95..1
+.8...6...
+790000000
+"""
+
+example1_list = [
+    [0,0,0,0,0,0,0,9,2],
+    [0,0,0,1,0,0,0,4,0],
+    [9,0,0,2,4,0,0,0,7],
+    [8,0,0,7,0,0,1,5,0],
+    [6,5,0,9,0,1,0,7,8],
+    [0,7,4,0,0,8,0,0,6],
+    [3,0,0,0,9,5,0,0,1],
+    [0,8,0,0,0,6,0,0,0],
+    [7,9,0,0,0,0,0,0,0]
+]
+
+def test_example():
+    m = reader.get_matrix(example1)
+    assert len(m) == 9
+    assert m[0] == [0,0,0,0,0,0,0,9,2]
+    assert m == example1_list
+
+def test_example_alt():
+    m = reader.get_matrix(example1_alt)
+    assert m == example1_list
\ No newline at end of file