is for tuples

[sattari]

BPO	38666
Nosy	@benjaminp

^{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 2019-11-02.14:05:58.307>
created_at = <Date 2019-11-02.12:52:53.568>
labels = ['3.8', 'type-bug', '3.7', 'invalid']
title = 'is for tuples'
updated_at = <Date 2019-11-02.14:05:58.297>
user = 'https://bugs.python.org/sattari'

bugs.python.org fields:

activity = <Date 2019-11-02.14:05:58.297>
actor = 'benjamin.peterson'
assignee = 'none'
closed = True
closed_date = <Date 2019-11-02.14:05:58.307>
closer = 'benjamin.peterson'
components = []
creation = <Date 2019-11-02.12:52:53.568>
creator = 'sattari'
dependencies = []
files = []
hgrepos = []
issue_num = 38666
keywords = []
message_count = 2.0
messages = ['355867', '355869']
nosy_count = 2.0
nosy_names = ['benjamin.peterson', 'sattari']
pr_nums = []
priority = 'normal'
resolution = 'not a bug'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue38666'
versions = ['Python 3.7', 'Python 3.8']

[sattari]

The following code gives different results interactive and script mode:

e = (1, 2)
f = (1, 2)
print(e is f)

[benjaminp]

"is" compares by identity not equality. Since tuples are immutable, the interpreter is free to reuse or not reuse the same tuple instance when it appears multiple times in a program. This is an implementation detail not a bug.