Source Code for Module instant.signatures

 1  """This module contains helper functions for working with checksums.""" 
 2   
 3  import hashlib 
 4  from .output import instant_assert, instant_debug, instant_error 
 5   
 6 -def compute_checksum(text="", filenames=[]): 
 7      """ 
 8      Get the checksum value of filename 
 9      modified based on Python24\Tools\Scripts\md5.py 
10      """ 
11      instant_assert(isinstance(text, str), "Expecting string.") 
12      instant_assert(isinstance(filenames, (list,tuple)), "Expecting sequence.") 
13       
14      m = hashlib.new('sha1') 
15      if text: 
16          m.update(text) 
17       
18      for filename in sorted(filenames):  
19          instant_debug("Adding file '%s' to checksum." % filename) 
20          try: 
21              fp = open(filename, 'rb') 
22          except IOError as e: 
23              instant_error("Can't open file '%s': %s" % (filename, e)) 
24           
25          try: 
26              while 1: 
27                  data = fp.read() 
28                  if not data: 
29                      break 
30                  m.update(data) 
31          except IOError as e: 
32              instant_error("I/O error reading '%s': %s" % (filename, e)) 
33           
34          fp.close()  
35       
36      return m.hexdigest().lower() 
37   
38   
39 -def _test(): 
40      signature = "(Test signature)" 
41      files = ["signatures.py", "__init__.py"] 
42      print() 
43      print("Signature:", repr(signature)) 
44      print("Checksum:", compute_checksum(signature, [])) 
45      print() 
46      print("Files:", files) 
47      print("Checksum:", compute_checksum("", files)) 
48      print() 
49   
50  if __name__ == "__main__": 
51      _test() 
52