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Line 6: − - Substraction+ − * Multiplication+ − / Division+ − ** Power+ − % Reminder+ − // Floor division (Reminder is removed)</nowiki>+ − == Equal + − != Not equal+ − > Greater+ − >= Greater or equal+ − < Smaller+ − <= Smaller or equal+ − <> Similar to !=</nowiki>+ − = Simple assignment+ − += Add and as+ − -= Substract and assignment+ − *= Multiply and assignment+ − /= Divide and assignment+ − %= Modulus and assignment+ − **= Exponent and assignment+ − //= Floor Divisionn and assignment</nowiki>+ − $ Binary AND+ − | Binary OR+ − ^ Binary XOR+ − ~ Binary complement+ − << Binary left shift+ − >> Binary right shift</nowiki>+ − and+ − or+ − not</nowiki>+ Line 54:
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Line 324: − ^ → Matches the beginning of a line+ − $ → Matches the end of a line+ − . → Matches any character+ − \s → Matches any whitespace+ − \S → Matches any non-whitespace+ − * → Repeats a character 0 or more times+ − *? → Repeats a character 0 or more times (non-greedy)+ − + → Repeats a character 1 or more times+ − +? → Repeats a character 1 or more times (non-greedy)+ − [aeiou] → Matches a single character in the listed set+ − [^XYZ] → Matches a single character NOT in the listed set+ − [a-z0-9] → The set of characters can include a range+ − ( → Indicates where string extraction is to start+ − ) → Indicates where string extraction is to end</nowiki> + Line 425:
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Line 868: − index-servers =+ − pypi+ − pypitest+ − + − [pypi]+ − repository=https://upload.pypi.org/legacy/+ − username=your_username+ − password=your_password+ − + − [pypitest]+ − repository=https://testpypi.python.org/pypi+ − username=your_username+ − password=your_password</nowiki>+ Line 823:
Line 958: − description-file = README.md</nowiki>+ − + − SPDX short identifier: MIT+ − + − Copyright <YEAR> <COPYRIGHT HOLDER>+ − + − Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:+ − + − The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.+ − + − THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.</nowiki>+ Line 850:
Line 985: − index-url= http://10.255.0.21/pypi/simple+ − trusted-host= 10.255.0.21</nowiki>+ Line 859:
Line 994: − index-servers =+ − pypi+ − pypitest+ − + − [pypi]+ − repository=https://pypi.python.org/pypi+ − username=+ − password=+ − + − [pypitest]+ − repository=https://test.pypi.org/legacy+ − username=+ − password=+ − </nowiki>+ Line 881:
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→Change PyPi
===Arithmetic===
===Arithmetic===
<nowiki>+ Addition
<nowiki>+ Addition
- Substraction
* Multiplication
/ Division
** Power
% Reminder
// Floor division (Reminder is removed)</nowiki>
===Comparison===
===Comparison===
<nowiki>
<nowiki>
== Equal
!= Not equal
> Greater
>= Greater or equal
< Smaller
<= Smaller or equal
<> Similar to !=</nowiki>
===Assignment===
===Assignment===
<nowiki>
<nowiki>
= Simple assignment
+= Add and as
-= Substract and assignment
*= Multiply and assignment
/= Divide and assignment
%= Modulus and assignment
**= Exponent and assignment
//= Floor Divisionn and assignment</nowiki>
===Bitwise operators===
===Bitwise operators===
They perform operations on binary terms. a= 8 → 100; b= 9 → 101; a & b → 100
They perform operations on binary terms. a= 8 → 100; b= 9 → 101; a & b → 100
<nowiki>
<nowiki>
$ Binary AND
| Binary OR
^ Binary XOR
~ Binary complement
<< Binary left shift
>> Binary right shift</nowiki>
===Logic===
===Logic===
<nowiki>
<nowiki>
and
or
not</nowiki>
===Membership operators===
===Membership operators===
==Variables==
==Variables==
===Numbers===
===Numbers===
====0 padding 2 digits====
<syntaxhighlight lang="python3">
print("{:02d}".format(1))
</syntaxhighlight>
===String===
===String===
String assingment:<br />
String assingment:<br />
Removes an item from a list.<br />
Removes an item from a list.<br />
example: a = [1, 2, 3, 4, 5] del a[0] returns [2, 3, 4, 5]
example: a = [1, 2, 3, 4, 5] del a[0] returns [2, 3, 4, 5]
<br />
====List comprehension====
flatten list<syntaxhighlight lang="python3">
def flatten(list_of_lists):
return [element for secondary_list in list_of_lists for element in secondary_list ]
a = [[1,2,3], [3,4,5], ["a", "b"]]
flatten(a)
Out[29]: [1, 2, 3, 3, 4, 5, 'a', 'b']
</syntaxhighlight><br />
====Tuple====
====Tuple====
</source>
</source>
===Print Exception===
<syntaxhighlight lang="python3">
import traceback
def bug():
my_dict = {'a': 9}
try:
return my_dict['b']
except KeyError:
print(traceback.format_exc())
return None
</syntaxhighlight><br />
==Loops==
==Loops==
===For===
===For===
==Regular Expressions==
==Regular Expressions==
<nowiki>
<nowiki>
^ → Matches the beginning of a line
$ → Matches the end of a line
. → Matches any character
\s → Matches any whitespace
\S → Matches any non-whitespace
* → Repeats a character 0 or more times
*? → Repeats a character 0 or more times (non-greedy)
+ → Repeats a character 1 or more times
+? → Repeats a character 1 or more times (non-greedy)
[aeiou] → Matches a single character in the listed set
[^XYZ] → Matches a single character NOT in the listed set
[a-z0-9] → The set of characters can include a range
( → Indicates where string extraction is to start
) → Indicates where string extraction is to end</nowiki>
\ → Escape character
\ → Escape character
===Regular Expression Module===
===Regular Expression Module===
return counter
return counter
</source>
</source>
==Run System Commands==
===Python >= 3.5===
<syntaxhighlight lang="python3">
def _run_command(command):
log.debug("Command: {}".format(command))
result = subprocess.run(command, shell=True, capture_output=True)
if result.stderr:
raise subprocess.CalledProcessError(
returncode=result.returncode,
cmd=result.args,
stderr=f"{result.stdout}\n{result.stderr}"
)
if result.stdout:
log.debug("Command Result: {}".format(result.stdout.decode('utf-8')))
return result
</syntaxhighlight>
==Class==
==Class==
'''Hiding attributes'''
'''Hiding attributes'''
attributes that start with a __ wont be visible to others<br />
attributes that start with a __ wont be visible to others<br />
===Subclasing builtins===
====Perfect dict subclass====
<syntaxhighlight lang="python3">
# has a ton of errors: https://stackoverflow.com/questions/3387691/how-to-perfectly-override-a-dict
class LowerDict(dict):
__slots__ = ()
def _process_args(mapping=(), **kwargs):
if hasattr(mapping, items):
mapping = getattr(mapping, items)()
return ((ensure_lower(k), v) for k, v in chain(mapping, getattr(kwargs, items)()))
def __init__(self, mapping=(), **kwargs):
super(LowerDict, self).__init__(self._process_args(mapping, **kwargs))
def __getitem__(self, k):
return super(LowerDict, self).__getitem__(ensure_lower(k))
def __setitem__(self, k, v):
return super(LowerDict, self).__setitem__(ensure_lower(k), v)
def __delitem__(self, k):
return super(LowerDict, self).__delitem__(ensure_lower(k))
def get(self, k, default=None):
return super(LowerDict, self).get(ensure_lower(k), default)
def setdefault(self, k, default=None):
return super(LowerDict, self).setdefault(ensure_lower(k), default)
def pop(self, k, v=_RaiseKeyError):
if v is _RaiseKeyError:
return super(LowerDict, self).pop(ensure_lower(k))
return super(LowerDict, self).pop(ensure_lower(k), v)
def update(self, mapping=(), **kwargs):
super(LowerDict, self).update(self._process_args(mapping, **kwargs))
def __contains__(self, k):
return super(LowerDict, self).__contains__(ensure_lower(k))
def copy(self): # don't delegate w/ super - dict.copy() -> dict :(
return type(self)(self)
@classmethod
def fromkeys(cls, keys, v=None):
return super(LowerDict, cls).fromkeys((ensure_lower(k) for k in keys), v)
def __repr__(self):
return '{0}({1})'.format(type(self).__name__, super(LowerDict, self).__repr__())
</syntaxhighlight>
====Not so perfect dict like object====
<syntaxhighlight lang="python3">
from collections.abc import MutableMapping
class TransformedDict(MutableMapping):
"""A dictionary that applies an arbitrary key-altering
function before accessing the keys"""
def __init__(self, *args, **kwargs):
self.store = dict()
self.update(dict(*args, **kwargs)) # use the free update to set keys
def __getitem__(self, key):
return self.store[self._keytransform(key)]
def __setitem__(self, key, value):
self.store[self._keytransform(key)] = value
def __delitem__(self, key):
del self.store[self._keytransform(key)]
def __iter__(self):
return iter(self.store)
def __len__(self):
return len(self.store)
def _keytransform(self, key):
return key
</syntaxhighlight>
==os.system()==
==os.system()==
To execute a Linux command from Python:
To execute a Linux command from Python:
nano ~/.pypirc
nano ~/.pypirc
<nowiki>[distutils]
<nowiki>[distutils]
index-servers =
pypi
pypitest
[pypi]
repository=https://upload.pypi.org/legacy/
username=your_username
password=your_password
[pypitest]
repository=https://testpypi.python.org/pypi
username=your_username
password=your_password</nowiki>
Adjust .pypirc permissions
Adjust .pypirc permissions
chmod 600 ~/.pypirc
chmod 600 ~/.pypirc
nano setup.cfg
nano setup.cfg
<nowiki>[metadata]
<nowiki>[metadata]
description-file = README.md</nowiki>
nano LICENSE
nano LICENSE
<nowiki>The MIT License
<nowiki>The MIT License
SPDX short identifier: MIT
Copyright <YEAR> <COPYRIGHT HOLDER>
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.</nowiki>
Test and upload
Test and upload
<source lang="bash">python setup.py register -r pypitest
<source lang="bash">python setup.py register -r pypitest
nano ~/.pip/pip.conf
nano ~/.pip/pip.conf
<nowiki>[global]
<nowiki>[global]
index-url= http://10.255.0.21/pypi/simple
trusted-host= 10.255.0.21</nowiki>
==Using pip behind proxy==
==Using pip behind proxy==
Create the file ~/.pypirc
Create the file ~/.pypirc
<nowiki>[distutils]
<nowiki>[distutils]
index-servers =
pypi
pypitest
[pypi]
repository=https://pypi.python.org/pypi
username=
password=
[pypitest]
repository=https://test.pypi.org/legacy
username=
password=
</nowiki>
Test
Test
python setup.py register -r pypi
python setup.py register -r pypi
python setup.py sdist upload -r pypi
python setup.py sdist upload -r pypi
== requirements.txt ==
=== Platform conditional ===
<syntaxhighlight lang="text">
psycopg2-binary~=2.9.7; platform_system == "Linux"
psycopg2~=2.9.6; platform_system == "Windows"
</syntaxhighlight>
==AWS boto3 EC2==
==AWS boto3 EC2==