[ python-Bugs-905389 ] str.join() intercepts TypeError raised by iterator

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Bugs item #905389, was opened at 2004-02-26 16:19
Message generated for change (Settings changed) made by rhettinger
You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=105470&aid=905389&group_id=5470

Category: Python Library
Group: Python 2.3
Status: Open
Resolution: None
Priority: 5
Submitted By: Lenard Lindstrom (kermode)
>Assigned to: Raymond Hettinger (rhettinger)
Summary: str.join() intercepts TypeError raised by iterator

Initial Comment:
For str.join(), if it is passed an iterator and that 
iterator raises a TypeError, that exception is caught 
by the join method and replaced by its own 
TypeError exception. SyntaxError and IndexError 
exceptions are uneffected.

Example:

Python 2.3.3 (#51, Dec 18 2003, 20:22:39) [MSC 
v.1200 32 bit (Intel)] on win32
...
IDLE 1.0.2      
>>> def gen(n):
	if not isinstance(n, int):
		raise TypeError, "gen() TypeError"
	if n<0:
		raise IndexError,  "gen() 
IndexError"
	for i in range(n):
		yield str(i)

		
>>> &#039;&#039;.join(gen(5))
&#039;01234&#039;
>>> &#039;&#039;.join(gen(-1))

Traceback (most recent call last):
  File "<pyshell#9>", line 1, in -toplevel-
    &#039;&#039;.join(gen(-1))
  File "<pyshell#7>", line 5, in gen
    raise IndexError, "gen() IndexError"
IndexError: gen() IndexError
>>> &#039;&#039;.join(gen(None))

Traceback (most recent call last):
  File "<pyshell#10>", line 1, in -toplevel-
    &#039;&#039;.join(gen(None))
TypeError: sequence expected, generator found
>>> 


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