Very fast Python library for .eml files parsing
fastmailparser
fastmailparser is a Python library for .eml files parsing. The main benefit is a performance: the library is much faster than python implementations.
Based on mailparse library using pyo3.
Benchmark
-------------------------------------------------------------------------------------------- benchmark: 2 tests -------------------------------------------------------------------------------------------
Name (time in ms) Min Max Mean StdDev Median IQR Outliers OPS Rounds Iterations
testfastmailparserparsemessage 1.8136 (1.0) 1.8938 (1.0) 1.8426 (1.0) 0.0176 (1.0) 1.8465 (1.0) 0.0277 (1.0) 180;0 542.7141 (1.0) 450 1
testmailparserparse_message 14.5583 (8.03) 15.8571 (8.37) 15.0264 (8.16) 0.2368 (13.49) 14.9702 (8.11) 0.2887 (10.42) 5;1 66.5495 (0.12) 32 1
Legend: Outliers: 1 Standard Deviation from Mean; 1.5 IQR (InterQuartile Range) from 1st Quartile and 3rd Quartile. OPS: Operations Per Second, computed as 1 / Mean
Installation
Use the package manager pip to install fastmail_parser.
pip install fast-mail-parserUsage
parse_email accepts the raw message as str or bytes and returns a PyMail. It raises ParseError if the payload cannot be parsed.
PyMail exposes the following attributes:
| Attribute | Type | Description | | --- | --- | --- | | subject | str | Subject header (empty string if missing). | | date | str | Date header (empty string if missing). | | text_plain | list[str] | All text/plain bodies. | | text_html | list[str] | All text/html bodies. | | headers | dict[str, str] | All message headers. | | attachments | list[PyAttachment] | Attachments (see below). |
Each PyAttachment has mimetype: str, filename: str, and content: bytes.
import sys
from fastmailparser import parse_email, ParseError
parse_email accepts both str and bytes; reading in binary mode is safest.
with open('message.eml', 'rb') as f:
message_payload = f.read()
try: email = parseemail(messagepayload) except ParseError as e: print("Failed to parse email:", e) sys.exit(1)
print("Subject:", email.subject) print("Date:", email.date)
headers is a dict[str, str].
for name, value in email.headers.items():
print(f"{name}: {value}")
textplain and texthtml are lists of strings (one entry per matching part).
for body in email.text_plain:
print("Plain text body:", body)
for body in email.text_html: print("HTML body:", body)
attachments is a list of PyAttachment objects.
for attachment in email.attachments:
print("Attachment:", attachment.filename)
print(" mimetype:", attachment.mimetype)
print(" size:", len(attachment.content), "bytes") # content is bytesContributing
Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.
Please make sure to update tests as appropriate.
See CONTRIBUTING.md for how to build from source, run the tests, and the PR conventions (linting, CI, DCO sign-off).
