探索Django utils

Posted November 16, 2018

Django utils 提供了很多实用的功能.

Crypto

Module: django.utils.crypto

get_random_string

获取随机字符串函数，默认是返回长度为12的随机字符串。可以通过参数传递长度.

from django.utils.crypto import get_random_string

get_random_string()

<\>Python

'5QxAxqyhsyJM'

#output

<\>Python

你可以传递参数，获取指定长度的字符串

get_random_string(50)

<\>Python

'lrWYnyxhnXpwmjHDzmdgTFaIi1j73cKD5fPDOPwuVBmmKxITYF'

#output

<\>Python

也可以指定字符串的选值范围

get_random_string(12, '0123456789')

<\>Python

'805379737758'

#output

<\>Python

Dates

Module: django.utils.dates

常用日期的集合，日期的人性化显示.

WEEKDAYS

from django.utils.dates import WEEKDAYS

<\>Python

WEEKDAYS = {
    0: _('Monday'), 1: _('Tuesday'), 2: _('Wednesday'), 3: _('Thursday'), 4: _('Friday'),
    5: _('Saturday'), 6: _('Sunday')
}

<\>Python

WEEKDAYS_ABBR

from django.utils.dates import WEEKDAYS_ABBR

<\>Python

WEEKDAYS_ABBR = {
    0: _('Mon'), 1: _('Tue'), 2: _('Wed'), 3: _('Thu'), 4: _('Fri'),
    5: _('Sat'), 6: _('Sun')
}

<\>Python

MONTHS

from django.utils.dates import MONTHS

<\>Python

MONTHS = {
    1: _('January'), 2: _('February'), 3: _('March'), 4: _('April'), 5: _('May'), 6: _('June'),
    7: _('July'), 8: _('August'), 9: _('September'), 10: _('October'), 11: _('November'),
    12: _('December')
}

<\>Python

DateFormat

Module: django.utils.dateformat

一个很棒的日期格式化模块

format

from django.utils.dateformat import format
from django.utils import timezone

now = timezone.now()    # datetime.datetime(2018, 11, 16, 6, 48, 41, 351928, tzinfo=<UTC>)
format(now, 'd M Y')

<\>Python

u'16 Nov 2018'

#output

<\>Python

日期和时间一起

format(now, 'd/m/Y H:i')

<\>Python

u'16/11/2018 06:48'

#output

<\>Python

DateParse

Module: django.utils.dateparse

将格式化后的字符串转为 date/time/datetime 对象. 如果字符串格式正确，但表示无效时间将会返回 None.

parse_date

from django.utils.dateparse import parse_date

parse_date('2018-11-16')

<\>Python

datetime.date(2018, 11, 16)

#output

<\>Python

parse_time

from django.utils.dateparse import parse_time

parse_time('14:54:02')

<\>Python

datetime.time(14, 54, 2)

#output

<\>Python

parse_datetime

from django.utils.dateparse import parse_datetime

parse_datetime('2018-11-16 14:54:02')

<\>Python

datetime.datetime(2018, 11, 16, 14, 54, 2)

#output

<\>Python

HTML

Module: django.utils.html

urlize

将文本中的网址转换为<a>标签

from django.utils.html import urlize

urlize('You guys should visit this website www.google.com')
print urlize('Please visit:  https://jackeygao.io')

<\>Python

'You guys should visit this website <a href="http://www.google.com">www.google.com</a>'
Please visit:  <a href="https://jackeygao.io">https://jackeygao.io</a>

#output

<\>Python

他也适用于email地址

urlize('Send me a message to [email protected]')

<\>Python

'Send me a message to <a href="mailto:[email protected]">[email protected]</a>'

#output

<\>Python

你也可以修剪链接显示部分长度, 不足处以'...'替代

urlize('Please visit https://jackeygao.io/words/django-exploring-utils.html', 24)

<\>Python

Please visit <a href="https://jackeygao.io/words/django-exploring-utils.html">https://jackeygao.io/...</a>

#output

<\>Python

escape

对html 特殊字符编码

from django.utils.html import escape

escape("<strong style='font-size: 12px'>escaped html</strong>")

<\>Python

'&lt;strong style=&#39;font-size: 12px&#39;&gt;escaped html&lt;/strong&gt;'

#output

<\>Python

这将导致已转义的字符串再次被转义

escaped_html = escape("<strong>escaped html</strong>")
# '&lt;strong&gt;escaped html&lt;/strong&gt;'

escape(escaped_html)
# '&amp;lt;strong&amp;gt;escaped html&amp;lt;/strong&amp;gt;'

<\>Python

如果不想这样, 请改用conditional_escape()

conditional_escape

escaped_html = conditional_escape("<strong>escaped html</strong>")
# '&lt;strong&gt;escaped html&lt;/strong&gt;'

conditional_escape(escaped_html)
# '&lt;strong&gt;escaped html&lt;/strong&gt;'

<\>Python

format_html

此函数类似格式化字符串(str.format()), 因为安全的原因推荐使用format_html.

from django.utils.html import format_html

format_html('<div class="alert {}">{}</>', 'warning', 'Watch out!')

<\>Python

'<div class="alert warning">Watch out!</>'

#output

<\>Python

安全的格式化 HTML 代码.

format_html('<div class="alert {}">{}</>', '<script>alert(1);</script>', 'Watch out!')

<\>Python

'<div class="alert &lt;script&gt;alert(1);&lt;/script&gt;">Watch out!</>'

#output

<\>Python

format_html_join

适用于快速用相同的方式格式化一组列表

format_html_join('\n', '<p>{}</p>', ['a', 'b', 'c'])

<\>Python

<p>a</p>\n<p>b</p>\n<p>c</p>

#output

<\>Python

另外一个例子

data = [
    ['success', 'Success message'],
    ['warning', 'Watch out!'],
    ['danger', 'Danger!!'],
]

format_html_join('\n', '<div class="alert {0}">{1}</div>', data)

<\>Python

<div class="alert success">Success message</div>\n
<div class="alert warning">Watch out!</div>\n
<div class="alert danger">Danger!!</div>

#output

<\>Python

和表格一起使用, 当然也可以和ul li一起使用.

format_html_join('\n', '<tr><td>{0}</td><td>{1}</td></tr>', ((u.first_name, u.last_name)
                                                            for u in users))

<\>Python

<tr><td>Vitor</td><td>Freitas</td></tr>\n
<tr><td>John</td><td>Duo</td></tr>\n
<tr><td>Peter</td><td>Croke</td></tr>\n
<tr><td>Elektra</td><td>Moore</td></tr>

#output

<\>Python

linebreaks

快速将\n转换为<br />

from django.utils.html import linebreaks

linebreaks('convert\ninto html paragraphs\ntest')

<\>Python

<p>convert<br />into html paragraphs<br />test</p>

#output

<\>Python

就是这样，我希望你也能找到一些有趣的函数，欢迎通过留言推荐.

𝔔

#好玩的Django