py: Fix printing of "inf" and "nan" floating point values.
diff --git a/py/objfloat.c b/py/objfloat.c
index eb59cc5..f74e12f 100644
--- a/py/objfloat.c
+++ b/py/objfloat.c
@@ -49,16 +49,16 @@
     char buf[16];
     mp_format_float(o->value, buf, sizeof(buf), 'g', 7, '\0');
     mp_print_str(print, buf);
-    if (strchr(buf, '.') == NULL && strchr(buf, 'e') == NULL) {
-        // Python floats always have decimal point
+    if (strchr(buf, '.') == NULL && strchr(buf, 'e') == NULL && strchr(buf, 'n') == NULL) {
+        // Python floats always have decimal point (unless inf or nan)
         mp_print_str(print, ".0");
     }
 #else
     char buf[32];
     sprintf(buf, "%.16g", (double) o->value);
     mp_print_str(print, buf);
-    if (strchr(buf, '.') == NULL && strchr(buf, 'e') == NULL) {
-        // Python floats always have decimal point
+    if (strchr(buf, '.') == NULL && strchr(buf, 'e') == NULL && strchr(buf, 'n') == NULL) {
+        // Python floats always have decimal point (unless inf or nan)
         mp_print_str(print, ".0");
     }
 #endif
diff --git a/tests/float/float1.py b/tests/float/float1.py
index bb67058..f670a63 100644
--- a/tests/float/float1.py
+++ b/tests/float/float1.py
@@ -7,6 +7,25 @@
 
 # float construction
 print(float(1.2))
+print(float("1.2"))
+print(float("+1"))
+print(float("1e1"))
+print(float("1e+1"))
+print(float("1e-1"))
+print(float("inf"))
+print(float("INF"))
+print(float("infinity"))
+print(float("INFINITY"))
+print(float("nan"))
+print(float("NaN"))
+try:
+    float("1e+")
+except ValueError:
+    print("ValueError")
+try:
+    float("1z")
+except ValueError:
+    print("ValueError")
 
 # unary operators
 print(bool(0.0))