This paper introduces an open source library for e-Book (digital textbook) log analysis, called OpenLA. An e-Book system is a useful system which records learning logs. Various analysis using these logs have been conducted. Although there are many common processes in preprocessing logs, the functions have been developed by per researcher. To reduce such redundant development, OpenLA provides useful modules to load course information, to convert learning logs into a more sophisticated representation, to extract the required information, and to visualize the data. OpenLA is written in the Python language and compatible with other Python libraries for analysis. This paper provides a brief explanation of each module, followed by re-implementation samples of related studies using OpenLA. The details about OpenLA is open to public at https://www.leds.ait.kyushu-u.ac.jp/achievements.