fix except case

- when redirect stdout to pipe but not tty, it throw exception.
- when have no content, it throw exception.
- remove reductant newline at end of file

bin/cheat

@@ -34,6 +34,7 @@ Examples:
     cheat -s ssh
 """
 
+from __future__ import print_function
 # require the dependencies
 from cheat import sheets, sheet
 from cheat.utils import colorize
@@ -50,7 +51,7 @@ if __name__ == '__main__':
 
     # list cheatsheets
     elif options['--list']:
-        print(sheets.list())
+        print(sheets.list(), end="")
 
     # create/edit cheatsheet
     elif options['--edit']:
@@ -58,8 +59,8 @@ if __name__ == '__main__':
 
     # search among the cheatsheets
     elif options['--search']:
-        print(colorize(sheets.search(options['<keyword>'])))
+        print(colorize(sheets.search(options['<keyword>'])), end="")
 
     # print the cheatsheet
     else:
-        print(colorize(sheet.read(options['<cheatsheet>'])))
+        print(colorize(sheet.read(options['<cheatsheet>'])), end="")

cheat/utils.py

@@ -10,6 +10,9 @@ def colorize(sheet_content):
     # only colorize if so configured
     if not 'CHEATCOLORS' in os.environ:
         return sheet_content
+    # only colorize if stdout is tty
+    if not sys.stdout.isatty():
+        return sheet_content
 
     try:
         from pygments import highlight
@@ -20,7 +23,10 @@ def colorize(sheet_content):
     except ImportError:
         return sheet_content
 
-    first_line = sheet_content.splitlines()[0]
+    lines = sheet_content.splitlines()
+    if len(lines) == 0:
+        return ""
+    first_line = lines[0]
     lexer = get_lexer_by_name('bash')
     if first_line.startswith('```'):
         sheet_content = '\n'.join(sheet_content.split('\n')[1:-2])