[Python-checkins] python/dist/src/Lib csv.py,1.4,1.5

2003年6月11日 20:01:57 -0700

Update of /cvsroot/python/python/dist/src/Lib
In directory sc8-pr-cvs1:/tmp/cvs-serv20789
Modified Files:
	csv.py 
Log Message:
SF Patch #744104: Remove eval() from csv
Eliminates the eval() step in the csv module resulting in better 
security, more clarity, and a little speed. 
The idea is to make successive attempts to coerce the string to 
a python type: 
 int(s), long(s), float(s), etc. 
As a by-product, eliminates a bare 'except' statement.
Index: csv.py
===================================================================
RCS file: /cvsroot/python/python/dist/src/Lib/csv.py,v
retrieving revision 1.4
retrieving revision 1.5
diff -C2 -d -r1.4 -r1.5
*** csv.py	19 May 2003 15:33:36 -0000	1.4
--- csv.py	12 Jun 2003 03:01:55 -0000	1.5
***************
*** 149,152 ****
--- 149,157 ----
 return self.writer.writerows(rows)

+ # Guard Sniffer's type checking against builds that exclude complex()
+ try:
+ complex
+ except NameError:
+ complex = float

 class Sniffer:
***************
*** 361,371 ****
 # subtracting from the likelihood of the first row being a header.

- def seval(item):
- """
- Strips parens from item prior to calling eval in an
- attempt to make it safer
- """
- return eval(item.replace('(', '').replace(')', ''))
- 
 rdr = reader(StringIO(sample), self.sniff(sample))

--- 366,369 ----
***************
*** 387,402 ****

 for col in columnTypes.keys():
! try:
 try:
! # is it a built-in type (besides string)?
! thisType = type(seval(row[col]))
! except OverflowError:
! # a long int?
! thisType = type(seval(row[col] + 'L'))
! thisType = type(0) # treat long ints as int
! except:
 # fallback to length of string
 thisType = len(row[col])

 if thisType != columnTypes[col]:
 if columnTypes[col] is None: # add new column type
--- 385,403 ----

 for col in columnTypes.keys():
! 
! for thisType in [int, long, float, complex]:
 try:
! thisType(row[col])
! break
! except ValueError, OverflowError:
! pass
! else:
 # fallback to length of string
 thisType = len(row[col])

+ # treat longs as ints
+ if thisType == long:
+ thisType = int
+ 
 if thisType != columnTypes[col]:
 if columnTypes[col] is None: # add new column type
***************
*** 418,423 ****
 else: # attempt typecast
 try:
! eval("%s(%s)" % (colType.__name__, header[col]))
! except:
 hasHeader += 1
 else:
--- 419,424 ----
 else: # attempt typecast
 try:
! colType(header[col])
! except ValueError, TypeError:
 hasHeader += 1
 else: