Generator-support in map() and filter()

[ragnark]

BPO	912738
Nosy	@tim-one

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

Show more details

GitHub fields:

assignee = None
closed_at = <Date 2004-03-09.20:11:51.000>
created_at = <Date 2004-03-09.14:13:35.000>
labels = ['interpreter-core', 'type-feature']
title = 'Generator-support in map() and filter()'
updated_at = <Date 2004-03-09.20:11:51.000>
user = 'https://bugs.python.org/ragnark'

bugs.python.org fields:

activity = <Date 2004-03-09.20:11:51.000>
actor = 'tim.peters'
assignee = 'none'
closed = True
closed_date = None
closer = None
components = ['Interpreter Core']
creation = <Date 2004-03-09.14:13:35.000>
creator = 'ragnark'
dependencies = []
files = []
hgrepos = []
issue_num = 912738
keywords = []
message_count = 2.0
messages = ['54112', '54113']
nosy_count = 2.0
nosy_names = ['tim.peters', 'ragnark']
pr_nums = []
priority = 'normal'
resolution = 'rejected'
stage = None
status = 'closed'
superseder = None
type = 'enhancement'
url = 'https://bugs.python.org/issue912738'
versions = []

[ragnark]

The current implementation of map() and filter()
returns a list when executed on any iterator, including
generators.

However, it may be very useful to map and filter the
output from generators without having to generate all
the data and allocate memory for it.

I would propose for map() and filter() to return a
generator-object instead of a list when the
input-argument is a generator.

[tim-one]

Logged In: YES
user_id=31435

It's (far) too late to change the signature of map() and filter
(). Look in the itertools module instead: its ifilter() and imap
() functions already do what you asked for (and more).