Codon Usage Analysis (CUA) has been accompanied by several web servers and independent programs written in several programming languages. Also this diversity speaks for the need of a reusable software that can be helpful in reading, manipulating and acting as a pipeline for such data and file formats. This kind of analyses use multiple tools to address the multifaceted aspects of CUA. So, we propose CodonU, a package written in Python language to integrate all aspects. It is compatible with existing file formats and can be used solely or with a group of other such packages. The proposed package incorporates various statistical measures necessary for codon usage analysis. The measures vary with nature of the sequences, viz. for nucleotide, codon adaptation index (CAI), codon bias index (CBI), tRNA adaptation index (tAI) etc. and for protein sequences Gravy score etc. Users can also perform the correspondence analysis (COA). This package also provides the liberty to generate graphics to users, and also develop phylogenetic tree. Capabilities of the proposed package were checked thoroughly on a genomic set of Staphylococcus aureus.