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+# pycksum - A Python implementation of the cksum algorithm
+
+[![Build](https://github.com/sobotklp/pycksum/workflows/CI/badge.svg?branch=master)](https://github.com/sobotklp/pycksum/actions?workflow=CI) [![PyVersion](https://img.shields.io/badge/python-3.7+-blue.svg)]() [![PyPiVersion](https://img.shields.io/pypi/v/pycksum.svg)](https://pypi.python.org/pypi/pycksum) [![License](https://img.shields.io/badge/license-MIT-yellow.svg)]()
+
+The `cksum` algorithm generates a checksum for a stream of data. While cksum is not cryptographically strong, it can be used to validate the integrity of transferred files.
+
+Pycksum includes a pure Python implementation of `cksum` as well as an efficient C extension that will automatically be used on platforms that support it.
+
+## Installation
+
+Install from PyPi using pip, a package manager for Python:
+
+```
+$ pip install pycksum
+```
+
+## Examples
+
+The simplest way to use pycksum is to just give it a string:
+
+```python
+import pycksum
+ck = pycksum.cksum("Any string")
+```
+
+You can pass in a file or an iterable:
+
+```python
+ck = pycksum.cksum( open("filename"))
+
+ck = pycksum.cksum( ["This", "love", "is", "taking", "its", "toll", "on me"])
+```
+
+If you have a lot of data to process, it's more memory-efficient to calculate the cksum incrementally:
+
+```python
+c = pycksum.Cksum()
+for data in input_fd:
+    c.add(data)
+ck = c.get_cksum()
+sz = c.get_size()
+```