Utility Functions
Frappe Framework comes with various utility functions to handle common operations for managing site-specific DateTime management, date and currency formatting, PDF generation, and much more.
These utility methods can be imported from the
frappe.utils
module (and its nested modules like
frappe.utils.logger
and
frappe.utils.data
) in any Python file of your Frappe App. This list is not at all exhaustive, you can take a peek at the Framework codebase to see what's available.
now
now()
Returns the current datetime in the format yyyy-mm-dd hh:mm:ss
from frappe.utils import now
now() # '2021-05-25 06:38:52.242515'
getdate
getdate(string_date=None)
Converts
string_date
(yyyy-mm-dd) to
datetime.date
object. If no input is provided, current date is returned. Throws an exception if
string_date
is an invalid date string.
from frappe.utils import getdate
getdate() # datetime.date(2021, 5, 25)
getdate('2000-03-18') # datetime.date(2000, 3, 18)
today
today()
Returns current date in the format yyyy-mm-dd .
from frappe.utils import today
today() # '2021-05-25'
add_to_date
add_to_date(date, years=0, months=0, weeks=0, days=0, hours=0, minutes=0, seconds=0, as_string=False, as_datetime=False)
`date`: A string representation or `datetime` object, uses the current `datetime` if `None` is passed
`as_string`: Return as string
`as_datetime`: If `as_string` is True and `as_datetime` is also True, returns a `datetime` string otherwise just the `date` string.
This function can be quite handy for doing date/datetime deltas, for instance, adding or substracting certain number of days from a particular date/datetime.
from datetime import datetime # from python std library
from frappe.utils import add_to_date
today = datetime.now().strftime('%Y-%m-%d')
print(today) # '2021-05-21'
after_10_days = add_to_date(datetime.now(), days=10, as_string=True)
print(after_10_days) # '2021-05-31'
add_to_date(datetime.now(), months=2) # datetime.datetime(2021, 7, 21, 15, 31, 18, 119999)
add_to_date(datetime.now(), days=10, as_string=True, as_datetime=True) # '2021-05-31 15:30:23.757661'
add_to_date(None, years=6) # datetime.datetime(2027, 5, 21, 15, 32, 31, 652089)
date_diff
date_diff(date_2, date_1)
Return the difference between the given two dates in days.
from frappe.utils import add_to_date, today, date_diff
date_1 = today()
date_2 = add_to_date(date_1, days=10)
print(date_diff(date_2, date_1)) #10
days_diff
days_diff(date_2, date_1)
Return the difference between the given two dates in days.
from frappe.utils import add_to_date, today, days_diff
date_1 = today()
date_2 = add_to_date(date_1, days=10)
print(days_diff(date_2, date_1)) #10
month_diff
month_diff(date_2, date_1)
Return the difference between the given two dates in months.
from frappe.utils import add_to_date, month_diff
date_1 = "2024-07-01"
date_2 = add_to_date(date_1, days=60)
print(month_diff(date_2, date_1)) #2
pretty_date
pretty_date(iso_datetime)
Takes an ISO time and returns a string representing how long ago the date represents. Very common in communication applications like instant messengers.
from frappe.utils import pretty_date, now, add_to_date
pretty_date(now()) # 'just now'
# Some example outputs:
# 1 hour ago
# 20 minutes ago
# 1 week ago
# 5 years ago
format_duration
format_duration(seconds, hide_days=False)
Converts the given duration value in seconds (float) to duration format.
from frappe.utils import format_duration
format_duration(50) # '50s'
format_duration(10000) # '2h 46m 40s'
format_duration(1000000) # '11d 13h 46m 40s'
# Convert days to hours
format_duration(1000000, hide_days=True) # '277h 46m 40s'
comma_and
comma_and(some_list, add_quotes=True)
Given a list or tuple
some_list
, returns a string of the format
1st item, 2nd item, .... and last item
. This function uses
frappe._
, so you don't have to worry about the translations for the word
and
. If
add_quotes
is
False
, returns the items without quotes, with quotes otherwise. If the type of
some_list
passed as an argument is something other than a list or tuple, it (
some_list
) is returned as it is.
from frappe.utils import comma_and
comma_and([1, 2, 3]) # "'1', '2' and '3'"
comma_and(['Apple', 'Ball', 'Cat'], add_quotes=False) # 'Apple, Ball and Cat'
comma_and('abcd') # 'abcd'
> There is also a
comma_or
function which is similar to
comma_and
except the separator, which is
or
in the case of
comma_or
.
money_in_words
money_in_words(number, main_currency=None, fraction_currency=None)
`number`: A floating point money amount
`main_currency`: Uses this as the main currency. If not given, tries to fetch from default settings or uses `INR` if not found there.
This function returns string in words with currency and fraction currency.
from frappe.utils import money_in_words
money_in_words(900) # 'INR Nine Hundred and Fifty Paisa only.'
money_in_words(900.50) # 'INR Nine Hundred and Fifty Paisa only.'
money_in_words(900.50, 'USD') # 'USD Nine Hundred and Fifty Centavo only.'
money_in_words(900.50, 'USD', 'Cents') # 'USD Nine Hundred and Fifty Cents only.'
validate_json_string
validate_json_string(string)
Raises
frappe.ValidationError
if the given
string
is a valid JSON (JavaScript Object Notation) string. You can use a
try-except
block to handle a call to this function as shown the code snippet below.
import frappe
from frappe.utils import validate_json_string
# No Exception thrown
validate_json_string('[]')
validate_json_string('[{}]')
validate_json_string('[{"player": "one", "score": 199}]')
try:
# Throws frappe.ValidationError
validate_json_string('invalid json')
except frappe.ValidationError:
print('Not a valid JSON string')
random_string
random_string(length)
This function generates a random string containing
length
number of characters. This can be useful for cryptographic or secret generation for some cases.
from frappe.utils import random_string
random_string(40) # 'mcrLCrlvkUdkaOe8m5xMI8IwDB8lszwJsWtZFveQ'
random_string(6) # 'htrB4L'
random_string(6) #'HNRirG'
unique
unique(seq)
seq
: An iterable / Sequence
This function returns a list of elements of the given sequence after removing the duplicates. Also, preserves the order, unlike:
list(set(seq))
.
from frappe.utils import unique
unique([1, 2, 3, 1, 1, 1]) # [1, 2, 3]
unique('abcda') # ['a', 'b', 'c', 'd']
unique(('Apple', 'Apple', 'Banana', 'Apple')) # ['Apple', 'Banana']
get_pdf
get_pdf(html, options=None, output=None)
`html`: HTML string to render
`options`: An optional `dict` for configuration
`output`: A optional `PdfFileWriter` object.
This function uses
pdfkit
and
pyPDF2
modules to generate PDF files from HTML. If
output
is provided, appends the generated pages to this object and returns it, otherwise returns a
byte
stream of the PDF.
For instance, generating and returning a PDF as response to a web request:
import frappe
from frappe.utils.pdf import get_pdf
@frappe.whitelist(allow_guest=True)
def generate_invoice():
cart = [{
'Samsung Galaxy S20': 10,
'iPhone 13': 80
}]
html = '<h1>Invoice from Star Electronics e-Store!</h1>'
# Add items to PDF HTML
html += '<ol>'
for item, qty in cart.items():
html += f'<li>{item} - {qty}</li>'
html += '</ol>'
# Attaching PDF to response
frappe.local.response.filename = 'invoice.pdf'
frappe.local.response.filecontent = get_pdf(html)
frappe.local.response.type = 'pdf'
get_abbr
get_abbr(string, max_len=2)
Returns an abbrivated (initials only) version of the given
string
with a maximum of
max_len
letters. It is extensively used in Frappe Framework and ERPNext to generate thumbnail or placeholder images.
from frappe.utils import get_abbr
get_abbr('Gavin') # 'G'
get_abbr('Coca Cola Company') # 'CC'
get_abbr('Mohammad Hussain Nagaria', max_len=3) # 'MHN'
validate_url
validate_url(txt, throw=False, valid_schemes=None)
`txt`: A string to check validity
`throw`: Weather to throw an exception if `txt` does not represent a valid URL, `False` by default
`valid_schemes`: A string or an iterable (list, tuple or set). If provided, checks the given URL's scheme against this.
This utility function can be used to check if a string represents a valid URL address.
from frappe.utils import validate_url
validate_url('google') # False
validate_url('https://google.com') # True
validate_url('https://google.com', throw=True) # throws ValidationError
validate_email_address
validate_email_address(email_str, throw=False)
Returns a string containing the email address or comma-separated list of valid email addresses present in the given
email_str
. If
throw
is
True
,
frappe.InvalidEmailAddressError
is thrown in case of no valid email address in present in the given string else an empty string is returned.
from frappe.utils import validate_email_address
# Single valid email address
validate_email_address('rushabh@erpnext.com') # 'rushabh@erpnext.com'
validate_email_address('other text, rushabh@erpnext.com, some other text') # 'rushabh@erpnext.com'
# Multiple valid email address
validate_email_address(
'some text, rushabh@erpnext.com, some other text, faris@erpnext.com, yet another no-emailic phrase.'
) # 'rushabh@erpnext.com, faris@erpnext.com'
# Invalid email address
validate_email_address('some other text') # ''
validate_phone_number
validate_phone_number(phone_number, throw=False)
Returns
True
if
phone_number
(string) is a valid phone number. If
phone_number
is invalid and
throw
is
True
,
frappe.InvalidPhoneNumberError
is thrown.
from frappe.utils import validate_phone_number
# Valid phone numbers
validate_phone_number('753858375') # True
validate_phone_number('+91-75385837') # True
# Invalid phone numbers
validate_phone_number('invalid') # False
validate_phone_number('87345%%', throw=True) # InvalidPhoneNumberError
frappe.cache()
cache()
Returns the redis connection, which is an instance of class
RedisWrapper
which is inherited from the
redis.Redis
class. You can use this connection to use the Redis cache to store/retrieve key-value pairs.
import frappe
cache = frappe.cache()
cache.set('name', 'frappe') # True
cache.get('name') # b'frappe'
frappe.sendmail()
sendmail(recipients=[], sender="", subject="No Subject", message="No Message", as_markdown=False, template=None, args=None, **kwargs)
`recipients`: List of recipients
`sender`: Email sender. Default is current user or default outgoing account
`subject`: Email Subject
`message`: (or `content`) Email Content
`as_markdown`: Convert content markdown to HTML
`template`: Name of html template (jinja) from templates/emails folder
`args`: Arguments for rendering the template
For most cases, the above arguments are sufficient but there are many other keyword arguments that can be passed to this function. To see all the keyword arguments, please have a look the implementation of this function (
frappe/__init__.py
).
This function can be used to send email using user's default Email Account or global default Email Account .
import frappe
recipients = [
'gavin@erpnext.com',
'hussain@erpnext.com'
]
frappe.sendmail(
recipients=recipients,
subject=frappe._('Birthday Reminder'),
template='birthday_reminder',
args=dict(
reminder_text=reminder_text,
birthday_persons=birthday_persons,
message=message,
),
header=_('Birthday Reminder 🎂')
)
Sample Jinja template file:
<!-- templates/emails/birthday_reminder.html -->
<div>
<div class="gray-container text-center">
<div>
{% for person in birthday_persons %}
{% if person.image %}
<img src="{{ person.image }}" title="{{ person.name }}"/>
{% endif %}
{% endfor %}
</div>
<div style="margin-top: 15px;">
<span>{{ reminder_text }}</span>
<p class="text-muted">{{ message }}</p>
</div>
</div>
Attaching Files
You can easily attach files to your email by passing a list of attachments to the
sendmail
function:
frappe.sendmail(
["faris@frappe.io", "hussain@frappe.io"],
message="## hello, *bro*"
attachments=[{"file_url": "/files/hello.png"}],
as_markdown=True
)
Notice how attachments are a list of dictionaries having a key
file_url
. You can find this
file_url
in a
File
document's
file_url
field.
filelock
File lock can be used to synchronize processes to avoid race conditions.
Example: Writing to a file can cause race condition if multiple writers are trying to write to a file. So we create a named lock so processes can see the lock and wait until it's avialable for writing.
from frappe.utils.synchronization import filelock
def update_important_config(config, file):
with filelock("config_name"):
json.dumps(config, file)