From 4875005153c1c3800740d7295d7807f27c60d7a9 Mon Sep 17 00:00:00 2001
From: Maxim Slipenko <max.slipenko@gmail.com>
Date: Mon, 20 Sep 2021 12:21:51 +0300
Subject: [PATCH] fix empty character

---
 turinglab/__main__.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/turinglab/__main__.py b/turinglab/__main__.py
index a916508..5b4133d 100644
--- a/turinglab/__main__.py
+++ b/turinglab/__main__.py
@@ -32,7 +32,9 @@ def main():
     test_data = []
 
     for test in args.tests:
-        test = test.replace(args.empty_character, 'λ')
+
+        if args.empty_character:
+            test = test.replace(args.empty_character, 'λ')
 
         tm = Emulator(program, test)