pycurl

library7.47.0pypypi✓ verified 26d ago

PycURL is a Python interface to the `libcurl` library, providing fast and feature-rich capabilities for network operations. It supports numerous protocols including HTTP, HTTPS, FTP, and more, exposing most of `libcurl`'s functionality like SSL, authentication, and proxy options. PycURL is often chosen for performance-critical applications and I/O multiplexing due to its speed. The current version is 7.45.7, with releases occurring periodically to incorporate `libcurl` updates and security fixes.

http-networking web-framework

pip install pycurl

github ↗package ↗homepage ↗docs ↗changelog ↗

INSTALL

IMPORT

SIG · PYCURL

pycurl

http-networkingpythonv7.47.0

Install

1.7s avg

Import

48ms

Disk

30MB

Pass rate

5/ 10

Env Coverage5 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v7.47.0 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

py 3.10–3.95 runs

build_error

glibc

py 3.10–3.95 runs

installs and imports cleanly · install 1.7s · import 0.038s · 32MB

30MB installed

● package 30MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

pycurl

✓ import pycurl

Curl

✓ import pycurl c = pycurl.Curl()

BytesIO

✓ from io import BytesIO

Commonly used with pycurl.WRITEDATA to capture response body in memory.

This quickstart demonstrates how to perform a basic GET request using PycURL. It initializes a Curl object, sets the URL, and uses `io.BytesIO` to capture the response body. Error handling for PycURL specific errors is included. It also highlights an optional step for using `certifi` for robust HTTPS certificate verification.

import pycurl from io import BytesIO def fetch_url(url): buffer = BytesIO() c = pycurl.Curl() c.setopt(c.URL, url) c.setopt(c.WRITEDATA, buffer) # Optional: For HTTPS, use certifi for certificate bundle # import certifi # c.setopt(c.CAINFO, certifi.where()) try: c.perform() status_code = c.getinfo(pycurl.RESPONSE_CODE) response_body = buffer.getvalue().decode('utf-8', errors='ignore') print(f"Status Code: {status_code}") print(f"Response Body (first 200 chars):\n{response_body[:200]}") except pycurl.error as e: print(f"PycURL error: {e}") finally: c.close() # Example usage fetch_url('https://httpbin.org/get')

pycurl --version

Debug

Known issues

gotchaPycURL is a wrapper around `libcurl`, a system library. Installing PycURL via pip often requires `libcurl` and its development headers (e.g., `libcurl4-openssl-dev` on Debian/Ubuntu, `curl` on macOS via Homebrew) to be present on your system. Without these, installation may fail or lead to runtime errors, especially when building from source.

fix

Ensure `libcurl` and its development packages are installed on your system before `pip install pycurl`.

affects: All versions

gotchaSSL backend mismatches can cause runtime `ImportError` (e.g., `pycurl: libcurl link-time ssl backend (...) is different from compile-time ssl backend (...)`). This occurs if PycURL is built against a different SSL library than what `libcurl` uses at runtime.

fix

During installation, explicitly tell `setup.py` which SSL backend to use via the `PYCURL_SSL_LIBRARY` environment variable (e.g., `export PYCURL_SSL_LIBRARY=openssl pip install pycurl`) or `setup.py` command-line options.

affects: All versions, particularly on custom builds or environments with multiple SSL libraries.

gotchaPycURL returns all network data as `bytes` objects. For text content, you must explicitly decode these `bytes` to `str` (e.g., using `.decode('utf-8')`). Conversely, when passing non-ASCII Unicode strings to `setopt` or `READFUNCTION`, they must first be encoded into `bytes` to avoid `UnicodeEncodeError` or `pycurl.error` (e.g., 'read function error/data error').

fix

Always decode received `bytes` to `str` for text, and encode `str` to `bytes` when sending non-ASCII data to PycURL. Use `errors='ignore'` or `errors='replace'` during decoding if dealing with unknown/malformed encodings.

affects: Python 3.x

deprecatedWhile `c.setopt(c.WRITEFUNCTION, buffer.write)` still works, as of PycURL 7.19.3, `c.setopt(c.WRITEDATA, buffer)` is generally preferred and simpler as it accepts any Python object with a `write` method (like `io.BytesIO`).

fix

Prefer `c.setopt(c.WRITEDATA, buffer)` over `WRITEFUNCTION` when providing a simple writeable object to capture response data.

affects: PycURL 7.19.3+

breakingThe `DEBUGFUNCTION` callback on Python 3 now expects its argument to be `bytes` instead of a (Unicode) `string`.

fix

Update `DEBUGFUNCTION` implementations on Python 3 to handle `bytes` arguments.

affects: PycURL 7.19.5.2 and later (on Python 3)

breakingThe `CURLMOPT_*` option constants, related to the multi interface, were moved from the `Easy` class to the `Multi` class. They remain available in the top-level `pycurl` module for backward compatibility.

fix

Access `CURLMOPT_*` constants either directly from the `pycurl` module (e.g., `pycurl.CURLMOPT_PIPELINING`) or from a `CurlMulti` instance (e.g., `multi_handle.CURLMOPT_PIPELINING`).

affects: PycURL 7.19.5.2 and later

Errors

Common errors & fixes

_curl.c: fatal error: curl/curl.h: No such file or directory

PycURL requires `libcurl` development headers (e.g., `libcurl-devel` or `libcurl4-openssl-dev`) to be installed on the system during its compilation.

fix

sudo apt-get install libcurl4-openssl-dev python3-dev (for Debian/Ubuntu) or sudo yum install libcurl-devel python3-devel (for RHEL/CentOS) before `pip install pycurl`.

ModuleNotFoundError: No module named 'pycurl'

The `pycurl` library is not installed in the Python environment where the code is being run.

fix

pip install pycurl

error: 'curl-config' is not found

The `curl-config` utility, which is part of the `libcurl` development package, is missing from the system's PATH, preventing `pycurl` from configuring itself correctly during installation.

fix

Install the `libcurl` development package: `sudo apt-get install libcurl4-openssl-dev` (Debian/Ubuntu) or `sudo yum install libcurl-devel` (RHEL/CentOS), then retry `pip install pycurl`.

pycurl.error: (60, "SSL certificate problem: unable to get local issuer certificate")

PycURL cannot verify the SSL certificate of the remote server, often due to an outdated or missing CA certificate bundle on the system or incorrect path configuration.

fix

Update your system's CA certificates (`sudo apt-get update && sudo apt-get install ca-certificates` on Debian/Ubuntu), or for testing/development, temporarily disable SSL verification by setting `c.setopt(pycurl.SSL_VERIFYPEER, 0)` and `c.setopt(pycurl.SSL_VERIFYHOST, 0)` (use with caution in production).

Upgrade

Version history

7.47.0latest on PyPI · released Jun 29, 2026

Audit

Dependencies

libcurlrequiredPycURL is a C extension that wraps the system's libcurl library. Its development headers are often required for successful installation, especially from source.

certifioptionalRecommended for managing SSL certificate bundles, especially when performing HTTPS requests.

Agent activity

9 hits · last 30 days

node

Resources

githubhttps://github.com/pycurl/pycurl ↗

packagehttps://pypi.org/project/pycurl/ ↗

homepagehttp://pycurl.io/ ↗

docshttp://pycurl.io/docs/latest/ ↗

changeloghttps://github.com/pycurl/pycurl/blob/master/ChangeLog ↗