

In [1]:

    
%install_ext https://raw.github.com/rocky/ipython-trepan/master/trepanmagic.py









    



Installed trepanmagic.py. To use it, type:
  %load_ext trepanmagic



In [2]:

    
%load_ext trepanmagic









    



trepanmagic.py loaded



In [3]:

    
%trepan /tmp/gcd.py 3 5









    



(/tmp/gcd.py:10): <module>
-> 10 """
(trepan3k) set autolist on
(trepan3k) next
(/tmp/gcd.py:11): <module>
-- 11 import sys
  6    	
  7    	check_args() raises an uncaught exception when given the wrong number
  8    	of parameters.
  9    	
 10    	"""
 11  ->	import sys
 12    	
 13    	def check_args():
 14    	    if len(sys.argv) != 3:
 15    	        # Rather than use sys.exit let's just raise an error
(trepan3k) next
(/tmp/gcd.py:40): <module>
-- 40 if __name__=='__main__':
 35    	        return None
 36    	    if a == 1 or b-a == 0:
 37    	        return a
 38    	    return gcd(b-a, a)
 39    	
 40  ->	if __name__=='__main__':
 41    	    check_args()
 42    	
 43    	    (a, b) = sys.argv[1:3]
 44    	    print("The GCD of %d and %d is %d" % (a, b, gcd(a, b)))
(trepan3k) eval?
eval: __name__=='__main__'






    Out[3]:





True






    



(trepan3k) break gcd
Breakpoint 1 set on calling function gcd()
Currently this is line 26 of file /tmp/gcd.py
(trepan3k) continue
(/tmp/gcd.py:26): gcd
xx 26 def gcd(a,b):
 21    	            print("** Expecting an integer, got: %s" % repr(sys.argv[i]))
 22    	            sys.exit(2)
 23    	            pass
 24    	        pass
 25    	
 26 B->	def gcd(a,b):
 27    	    """ GCD. We assume positive numbers"""
 28    	
 29    	    # Make: a <= b
 30    	    if a > b:
(trepan3k) backtrace
->0 gcd(a=3, b=5) called from file '/tmp/gcd.py' at line 26
##1 <module> exec()
     '/tmp/gcd.py' at line 44
(trepan3k) continue
(/tmp/gcd.py:26): gcd
xx 26 def gcd(a,b):
 21    	            print("** Expecting an integer, got: %s" % repr(sys.argv[i]))
 22    	            sys.exit(2)
 23    	            pass
 24    	        pass
 25    	
 26 B->	def gcd(a,b):
 27    	    """ GCD. We assume positive numbers"""
 28    	
 29    	    # Make: a <= b
 30    	    if a > b:
(trepan3k) backtrace
->0 gcd(a=2, b=3) called from file '/tmp/gcd.py' at line 26
##1 gcd(a=3, b=5) called from file '/tmp/gcd.py' at line 38
##2 <module> exec()
     '/tmp/gcd.py' at line 44
(trepan3k) delete 1
Deleted breakpoint 1
(trepan3k) continue
(/tmp/gcd.py:26): gcd
xx 26 def gcd(a,b):
 21    	            print("** Expecting an integer, got: %s" % repr(sys.argv[i]))
 22    	            sys.exit(2)
 23    	            pass
 24    	        pass
 25    	
 26  ->	def gcd(a,b):
 27    	    """ GCD. We assume positive numbers"""
 28    	
 29    	    # Make: a <= b
 30    	    if a > b:
(trepan3k) continue
The GCD of 3 and 5 is 1
The program finished - quit or restart
(/tmp/gcd.py:37): gcd
xx 37         return a
 32    	       pass
 33    	
 34    	    if a <= 0:
 35    	        return None
 36    	    if a == 1 or b-a == 0:
 37  ->	        return a
 38    	    return gcd(b-a, a)
 39    	
 40    	if __name__=='__main__':
 41    	    check_args()
(trepan3k) quit