import and compile() do not treat trailing whitespace the same #48512

mseaborn · 2008-11-05T10:56:29Z

BPO	4262
Nosy	@brettcannon, @terryjreedy

^{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 2010-04-29.17:44:36.700>
created_at = <Date 2008-11-05.10:56:28.572>
labels = ['interpreter-core', 'type-bug', 'invalid']
title = 'import and compile() do not treat trailing whitespace the same'
updated_at = <Date 2010-04-29.17:44:36.699>
user = 'https://bugs.python.org/mseaborn'

bugs.python.org fields:

activity = <Date 2010-04-29.17:44:36.699>
actor = 'terry.reedy'
assignee = 'none'
closed = True
closed_date = <Date 2010-04-29.17:44:36.700>
closer = 'terry.reedy'
components = ['Interpreter Core']
creation = <Date 2008-11-05.10:56:28.572>
creator = 'mseaborn'
dependencies = []
files = []
hgrepos = []
issue_num = 4262
keywords = []
message_count = 2.0
messages = ['75521', '75617']
nosy_count = 3.0
nosy_names = ['brett.cannon', 'terry.reedy', 'mseaborn']
pr_nums = []
priority = 'normal'
resolution = 'not a bug'
stage = None
status = 'closed'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue4262'
versions = ['Python 2.5']

mseaborn · 2008-11-05T10:56:28Z

compile() raises a SyntaxError if the source code it is given contains
trailing spaces or a trailing carriage return character, but this does
happen if the same source code is imported or executed.

import subprocess

data = "if True:\n  pass\n  "
filename = "/tmp/test.py"
fh = open(filename, "w")
fh.write(data)
fh.close()
subprocess.check_call(["python", filename])
subprocess.check_call(["python", "-c", "import test"], cwd="/tmp")
compile(data, filename, "exec")

This gives:

Traceback (most recent call last):
  File "whitespace.py", line 11, in <module>
    compile(data, filename, "exec")
  File "/tmp/test.py", line 3
    
SyntaxError: invalid syntax

This also happens if the data is changed to:
data = "if True:\n pass\r"

terryjreedy · 2008-11-07T21:47:56Z

Both differences are covered in the 2.x docs:

"When compiling multi-line statements, two caveats apply: line endings
must be represented by a single newline character ('\n'), and the input
must be terminated by at least one newline character.

The \r difference is not really a difference because \r is replaced by
\n before import starts compiling. I suspect that EOF effectively gets
converted to \n also. The doc issue is that 'must be terminated...' is
not always true.

This caveat is missing in 3.0, even though the limitation is the same.
see bpo-4118.

I thought this was discussed in a c.l.p thread.

mseaborn mannequin added interpreter-core (Objects, Python, Grammar, and Parser dirs) type-bug An unexpected behavior, bug, or error labels Nov 5, 2008

terryjreedy added the invalid label Nov 7, 2008

terryjreedy closed this as completed Apr 29, 2010

ezio-melotti transferred this issue from another repository Apr 10, 2022

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

import and compile() do not treat trailing whitespace the same #48512

import and compile() do not treat trailing whitespace the same #48512

mseaborn mannequin commented Nov 5, 2008

mseaborn mannequin commented Nov 5, 2008

terryjreedy commented Nov 7, 2008

import and compile() do not treat trailing whitespace the same #48512

import and compile() do not treat trailing whitespace the same #48512

Comments

mseaborn mannequin commented Nov 5, 2008

mseaborn mannequin commented Nov 5, 2008

terryjreedy commented Nov 7, 2008