@ -561,19 +561,20 @@ from dateutil.tz import UTC, tzlocal, gettz
```python
<D/DTn> = D/DT.today() # Current local date or naive datetime.
<DTn> = DT.utcnow() # Naive datetime from current UTC time.
<DTa> = DT.now(<tz>) # Aware datetime from current tz time.
<DTa> = DT.now(<tzinfo>) # Aware datetime from current tz time.
```
* **To extract time use `'<DTn>.time()'` or `'<DTa>.timetz()'`.**
### Timezone
```python
<tz> = UTC # UTC timezone. London without DST.
<tz> = tzlocal() # Local timezone.
<tz> = gettz('<Cont.>/<City>') # Timezone from 'Continent/City_Name' str.
<tzinfo> = UTC # UTC timezone. London without DST.
<tzinfo> = tzlocal() # Local timezone.
<tzinfo> = gettz('<Cont.>/<City>') # Timezone from 'Continent/City_Name' str.
```
```python
<DTa> = <DT>.astimezone(<tz>) # Datetime, converted to passed timezone.
<Ta/DTa> = <T/DT>.replace(tzinfo=<tz>) # Unconverted object with new timezone.
<DTa> = <DT>.astimezone(<tzinfo>) # Datetime, converted to passed timezone.
<Ta/DTa> = <T/DT>.replace(tzinfo=<tzinfo>) # Unconverted object with new timezone.
```
### Encode
@ -581,7 +582,7 @@ from dateutil.tz import UTC, tzlocal, gettz
<D/T/DT> = D/T/DT.fromisoformat('<iso>') # Object from ISO string.
<DT> = DT.strptime(<str>, '<format>') # Datetime from str, according to format.
<D/DTn> = D/DT.fromordinal(<int>) # D/DTn from days since Christ.
<DTa> = DT.fromtimestamp(<real>, <tz>) # DTa from seconds since Epoch in tz time.
<DTa> = DT.fromtimestamp(<real>, <tz.>) # DTa from seconds since Epoch in tz time.
```
* **ISO strings come in following forms: `'YYYY-MM-DD'`, `'HH:MM:SS.ffffff[±<offset>]'`, or both separated by `'T'`. Offset is formatted as: `'HH:MM'`.**
* **On Unix systems Epoch is `'1970-01-01 00:00 UTC'`, `'1970-01-01 01:00 CET'`, ...**
@ -601,10 +602,15 @@ from dateutil.tz import UTC, tzlocal, gettz
>>> dt.strftime("%A, %dth of %B '%y, %I:%M%p %Z")
"Thursday, 14th of May '15, 11:39PM UTC+02:00"
```
* **For abbreviated weekday and month use `'%a'` and `'%b'`.**
#### Rest of the codes:
* **`'a'` - Weekday, abbreviated name.**
* **`'b'` - Month, abbreviated name.**
### Arithmetics
```python
<D/DT> = <D/DT> ± <TD>
<TD> = <TD> ± <TD>
<TD> = <TD> */ <real>
<float> = <TD> / <TD>
```
Arguments
@ -1277,8 +1283,10 @@ Open
**Opens a file and returns a corresponding file object.**
* **`'encoding=None'` means default encoding is used, which is platform dependent. Best practice is to use `'encoding="utf-8"'` whenever possible.**
* **`'endline=None'` means all different end of line combinations are converted to '\n' on read, while on write all '\n' characters are converted to system's default line separator.**
### Modes
* **`'r'` - Read (default).**
@ -1295,7 +1303,8 @@ Open
```python
<file>.seek(0) # Moves to the start of the file.
<file>.seek(offset) # Moves 'offset' chars/bytes from the start.
<file>.write(<str/bytes>) # Writes a string or bytes object.
<file>.writelines(<list>) # Writes a list of strings or bytes objects.
<file>.writelines(<coll.>) # Writes a coll. of strings or bytes objects.
<file>.flush() # Flushes write buffer.
```
* **Methods do not add or strip trailing newlines.**
* **Methods do not add or strip trailing newlines, even writelines().**
### Read Text from File
```python
@ -1331,21 +1340,26 @@ Path
----
```python
from os import path, listdir
from glob import glob
```
```python
<bool> = path.exists('<path>')
<bool> = path.isfile('<path>')
<bool> = path.isdir('<path>')
<list> = listdir('<path>')
```
```python
>>> from glob import glob
>>> glob('../*.gif')
['1.gif', 'card.gif']
<list> = listdir('<path>') # List of filenames located at 'path'.
<list> = glob('<pattern>') # Filenames matching the wildcard pattern.
```
### Pathlib
```python
from pathlib import Path
```
```python
cwd = Path()
<Path> = Path('<path>' [, '<path>', <Path>, ...])
<Path> = <Path> / '<dir>' / '<file>'
@ -1355,11 +1369,11 @@ cwd = Path()
<bool> = <Path>.exists()
<bool> = <Path>.is_file()
<bool> = <Path>.is_dir()
<iter> = <Path>.iterdir()
```
```python
<iter> = <Path>.glob('<pattern>')
<iter> = <Path>.iterdir() # Iterator of filenames located at path.
<iter> = <Path>.glob('<pattern>') # Filenames matching the wildcard pattern.
```
```python
@ -1711,7 +1725,7 @@ class MyMetaClass(type):
* **New() can also be called directly, usually from a new() method of a child class (**`def __new__(cls): return super().__new__(cls)`**), in which case init() is not called.**
### Metaclass Attribute
**When class is created it checks if it has metaclass defined. If not, it recursively checks if any of his parents has it defined and eventually comes to type().**
**Right before a class is created it checks if it has metaclass defined. If not, it recursively checks if any of his parents has it defined and eventually comes to type().**
```python
class MyClass(metaclass=MyMetaClass):
@ -1723,7 +1737,12 @@ class MyClass(metaclass=MyMetaClass):
('abcde', 12345)
```
#### Type diagram (str is an instance of type, ...):
### Type Diagram
```python
type(MyClass) == MyMetaClass # MyClass is an instance of MyMetaClass.
type(MyMetaClass) == type # MyMetaClass is an instance of type.
```
```text
+---------+-------------+
| Classes | Metaclasses |
@ -1736,7 +1755,12 @@ class MyClass(metaclass=MyMetaClass):
+---------+-------------+
```
#### Inheritance diagram (str is a subclass of object, ...):
### Inheritance Diagram
```python
MyClass.__base__ == object # MyClass is a subclass of object.
MyMetaClass.__base__ == type # MyMetaClass is a subclass of type.
<pre><codeclass="python language-python hljs"><D/DTn> = D/DT.today() <spanclass="hljs-comment"># Current local date or naive datetime.</span>
<DTn> = DT.utcnow() <spanclass="hljs-comment"># Naive datetime from current UTC time.</span>
<DTa> = DT.now(<tz>)<spanclass="hljs-comment"># Aware datetime from current tz time.</span>
<DTa> = DT.now(<tzinfo>) <spanclass="hljs-comment"># Aware datetime from current tz time.</span>
</code></pre>
<ul>
<li><strong>To extract time use <codeclass="python hljs"><spanclass="hljs-string">'<DTn>.time()'</span></code> or <codeclass="python hljs"><spanclass="hljs-string">'<DTa>.timetz()'</span></code>.</strong></li>
</ul>
<h3id="timezone">Timezone</h3>
<pre><codeclass="python language-python hljs"><tz> = UTC <spanclass="hljs-comment"># UTC timezone. London without DST.</span>
<tz> = tzlocal() <spanclass="hljs-comment"># Local timezone.</span>
<tz> = gettz(<spanclass="hljs-string">'<Cont.>/<City>'</span>) <spanclass="hljs-comment"># Timezone from 'Continent/City_Name' str.</span>
<pre><codeclass="python language-python hljs"><tzinfo> = UTC <spanclass="hljs-comment"># UTC timezone. London without DST.</span>
<tzinfo> = tzlocal() <spanclass="hljs-comment"># Local timezone.</span>
<tzinfo> = gettz(<spanclass="hljs-string">'<Cont.>/<City>'</span>) <spanclass="hljs-comment"># Timezone from 'Continent/City_Name' str.</span>
<Ta/DTa> = <T/DT>.replace(tzinfo=<tzinfo>) <spanclass="hljs-comment"># Unconverted object with new timezone.</span>
</code></pre>
<h3id="encode">Encode</h3>
<pre><codeclass="python language-python apache hljs"><D/T/DT> = D/T/DT.fromisoformat(<spanclass="hljs-string">'<iso>'</span>) <spanclass="hljs-comment"># Object from ISO string.</span>
<DT> = DT.strptime(<str>, <spanclass="hljs-string">'<format>'</span>) <spanclass="hljs-comment"># Datetime from str, according to format.</span>
<D/DTn> = D/DT.fromordinal(<int>) <spanclass="hljs-comment"># D/DTn from days since Christ.</span>
<DTa> = DT.fromtimestamp(<real>, <tz>)<spanclass="hljs-comment"># DTa from seconds since Epoch in tz time.</span>
<DTa> = DT.fromtimestamp(<real>, <tz.>) <spanclass="hljs-comment"># DTa from seconds since Epoch in tz time.</span>
</code></pre>
<ul>
<li><strong>ISO strings come in following forms: <codeclass="python hljs"><spanclass="hljs-string">'YYYY-MM-DD'</span></code>, <codeclass="python hljs"><spanclass="hljs-string">'HH:MM:SS.ffffff[±<offset>]'</span></code>, or both separated by <codeclass="python hljs"><spanclass="hljs-string">'T'</span></code>. Offset is formatted as: <codeclass="python hljs"><spanclass="hljs-string">'HH:MM'</span></code>.</strong></li>
@ -631,11 +634,15 @@ shuffle(<list>)
<spanclass="hljs-meta">>>></span>dt.strftime(<spanclass="hljs-string">"%A, %dth of %B '%y, %I:%M%p %Z"</span>)
<spanclass="hljs-string">"Thursday, 14th of May '15, 11:39PM UTC+02:00"</span>
<li><strong>For abbreviated weekday and month use <codeclass="python hljs"><spanclass="hljs-string">'%a'</span></code> and <codeclass="python hljs"><spanclass="hljs-string">'%b'</span></code>.</strong></li>
<li><strong><codeclass="python hljs"><spanclass="hljs-string">'encoding=None'</span></code> means default encoding is used, which is platform dependent. Best practice is to use <codeclass="python hljs"><spanclass="hljs-string">'encoding="utf-8"'</span></code> whenever possible.</strong></li>
<li><strong><codeclass="python hljs"><spanclass="hljs-string">'endline=None'</span></code> means all different end of line combinations are converted to '\n' on read, while on write all '\n' characters are converted to system's default line separator.</strong></li>
<pre><codeclass="python language-python hljs"><file>.seek(<spanclass="hljs-number">0</span>) <spanclass="hljs-comment"># Moves to the start of the file.</span>
<file>.seek(offset) <spanclass="hljs-comment"># Moves 'offset' chars/bytes from the start.</span>
<file>.seek(<spanclass="hljs-number">0</span>, <spanclass="hljs-number">2</span>) <spanclass="hljs-comment"># Moves to the end of the file.</span>
<pre><codeclass="python language-python hljs"><str/bytes> = <file>.read(size=<spanclass="hljs-number">-1</span>) <spanclass="hljs-comment"># Reads 'size' chars/bytes or until EOF.</span>
<str/bytes> = <file>.readline() <spanclass="hljs-comment"># Returns a line.</span>
@ -1178,11 +1190,11 @@ value = args.<name>
<str/bytes> = next(<file>) <spanclass="hljs-comment"># Returns a line using buffer. Do not mix.</span>
</code></pre>
<pre><codeclass="python language-python hljs"><file>.write(<str/bytes>) <spanclass="hljs-comment"># Writes a string or bytes object.</span>
<file>.writelines(<list>) <spanclass="hljs-comment"># Writes a list of strings or bytes objects.</span>
<file>.writelines(<coll.>)<spanclass="hljs-comment"># Writes a coll. of strings or bytes objects.</span>
<pre><codeclass="python language-python hljs"><list> = listdir(<spanclass="hljs-string">'<path>'</span>) <spanclass="hljs-comment"># List of filenames located at 'path'. </span>
<list> = glob(<spanclass="hljs-string">'<pattern>'</span>) <spanclass="hljs-comment"># Filenames matching the wildcard pattern.</span>
<pre><codeclass="python language-python hljs"><iter> = <Path>.iterdir() <spanclass="hljs-comment"># Iterator of filenames located at path.</span>
<iter> = <Path>.glob(<spanclass="hljs-string">'<pattern>'</span>) <spanclass="hljs-comment"># Filenames matching the wildcard pattern.</span>
</code></pre>
<pre><codeclass="python language-python hljs"><str> = str(<Path>) <spanclass="hljs-comment"># Returns path as a string.</span>
<tup.> = <Path>.parts <spanclass="hljs-comment"># Returns all components as strings.</span>
<li><strong>New() can also be called directly, usually from a new() method of a child class (</strong><codeclass="python hljs"><spanclass="hljs-function"><spanclass="hljs-keyword">def</span><spanclass="hljs-title">__new__</span><spanclass="hljs-params">(cls)</span>:</span><spanclass="hljs-keyword">return</span> super().__new__(cls)</code><strong>), in which case init() is not called.</strong></li>
<p><strong>When class is created it checks if it has metaclass defined. If not, it recursively checks if any of his parents has it defined and eventually comes to type().</strong></p>
<p><strong>Right before a class is created it checks if it has metaclass defined. If not, it recursively checks if any of his parents has it defined and eventually comes to type().</strong></p>
Jure Šorn
5 years ago