53 lines
1.1 KiB
Bash
Executable file
53 lines
1.1 KiB
Bash
Executable file
#!/usr/bin/env bash
|
|
#
|
|
# Copyright (c) 2019 The Bitcoin Core developers
|
|
# Distributed under the MIT software license, see the accompanying
|
|
# file COPYING or http://www.opensource.org/licenses/mit-license.php.
|
|
#
|
|
# Detect when a mutable list or dict is used as a default parameter value in a Python function.
|
|
|
|
export LC_ALL=C
|
|
EXIT_CODE=0
|
|
OUTPUT=$(git grep -E '^\s*def [a-zA-Z0-9_]+\(.*=\s*(\[|\{)' -- "*.py")
|
|
if [[ ${OUTPUT} != "" ]]; then
|
|
echo "A mutable list or dict seems to be used as default parameter value:"
|
|
echo
|
|
echo "${OUTPUT}"
|
|
echo
|
|
cat << EXAMPLE
|
|
This is how mutable list and dict default parameter values behave:
|
|
|
|
>>> def f(i, j=[], k={}):
|
|
... j.append(i)
|
|
... k[i] = True
|
|
... return j, k
|
|
...
|
|
>>> f(1)
|
|
([1], {1: True})
|
|
>>> f(1)
|
|
([1, 1], {1: True})
|
|
>>> f(2)
|
|
([1, 1, 2], {1: True, 2: True})
|
|
|
|
The intended behaviour was likely:
|
|
|
|
>>> def f(i, j=None, k=None):
|
|
... if j is None:
|
|
... j = []
|
|
... if k is None:
|
|
... k = {}
|
|
... j.append(i)
|
|
... k[i] = True
|
|
... return j, k
|
|
...
|
|
>>> f(1)
|
|
([1], {1: True})
|
|
>>> f(1)
|
|
([1], {1: True})
|
|
>>> f(2)
|
|
([2], {2: True})
|
|
EXAMPLE
|
|
EXIT_CODE=1
|
|
fi
|
|
exit ${EXIT_CODE}
|