Python基础学习代码之错误和异常

def func1():
 try:
 return float('abc')
 except ValueError,e:
 print e
def func2():
 try:
 astr = 'abc'
 float(astr)
 except ValueError:
 astr = None
 return astr
def func3():
 try:
 astr = 'abc'
 float(astr)
 except ValueError:
 astr = 'count not convert non-number to float'
 return astr
def safe_float(argment):
 try:
 retval = float(argment)
 except ValueError:
 retval = 'count not convert non-number to float'
 except TypeError:
 retval = 'object type cannot be convert to float'
 return retval
def func4(argment):
 try:
 retval = float(argment)
 except (ValueError,TypeError):
 retval = 'argment must be a number or numeric string'
 return retval
def func5(argment):
 try:
 retval = float(argment)
 except ValueError,e:
 print e
 print type(e)
 print e.__class__
 print e.__class__.__doc__
 print e.__class__.__name__
def func6(argment):
 try:
 retval = float(argment)
 except (ValueError,TypeError),e:
 retval = str(e)
 return retval
def main():
 'handles all the data processing'
 log = open('e:\cardlog.txt','w')
 try:
 ccfile = open('e:\cardlog.txt','r')
 txns = ccfile.readlines()
 except IOError,e:
 log.write('no txns this month
')
 log.close()
 return
 ccfile.close()
 total = 0.00
 log.write('account log:
')
 for eachtxn in txns:
 result = func6(eachtxn)
 if isinstance(result,float):
 total += result
 log.write('data...processed
')
 else:
 log.write('ignored:%s'%result)
 print '$%.2f newbalance' % total
 log.close()
#if __name__ == '__main__':
# main()
def func7():
 assert 1 == 0
def func8():
 try:
 assert 0 == 1,'one does not equal zero'
 except AssertionError,e:
 print '%s:%s' % (e.__class__.__name__,e)
#assert
def func9(expr,args=None):
 if __debug__ and not expr:
 raise AssertionError,args
def func10():
 try:
 float('abc')
 except:
 import sys
 exect = sys.exc_info()
 return exect
def func11():
 try:
 f = open('test.txt')
 except:
 return None
 else:
 return f
def func12():
 try:
 raw_input('input data:')
 except (EOFError,KeyboardInterrupt):
 return None
import math,cmath
def safe_sqrt(data):
 try:
 ret = math.sqrt(data)
 except ValueError:
 ret = cmath.sqrt(data)
 return ret
import sys
def func13():
 try:
 s = raw_input('Enter something-->')
 except EOFError:
 print '
Why did you do an EOF on me?'
 sys.exit(0)
 except:
 print '
Some error/exception occurred.'
 print 'done'
func13()