py/mpz: Skip separators when running out of digits to print.

This commit fixes the addition of a stray separator before the number when printing an MPZ-backed integer and the first group is three digits long. This fixes micropython#8984. Signed-off-by: Alessandro Gatti <[email protected]>
picoscratch · Sep 26, 2024 · 43b05af · 43b05af
1 parent b0ba151
commit 43b05af
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Showing 2 changed files with 16 additions and 1 deletion.
diff --git a/py/mpz.c b/py/mpz.c
@@ -1717,7 +1717,7 @@ size_t mpz_as_str_inpl(const mpz_t *i, unsigned int base, const char *prefix, ch
                 break;
             }
         }
-        if (comma && (s - last_comma) == 3) {
+        if (!done && comma && (s - last_comma) == 3) {
             *s++ = comma;
             last_comma = s;
         }

diff --git a/tests/basics/string_format_intbig.py b/tests/basics/string_format_intbig.py
@@ -0,0 +1,15 @@
+# basic functionality test for {} format string using large integers
+
+
+def test(fmt, *args):
+    print("{:8s}".format(fmt) + ">" + fmt.format(*args) + "<")
+
+
+# Separator formatter
+
+test("{:,}", 123_456_789_012_345_678_901_234_567)
+test("{:,}", 23_456_789_012_345_678_901_234_567)
+test("{:,}", 3_456_789_012_345_678_901_234_567)
+test("{:,}", -123_456_789_012_345_678_901_234_567)
+test("{:,}", -23_456_789_012_345_678_901_234_567)
+test("{:,}", -3_456_789_012_345_678_901_234_567)