Career
During his time in office he sat with the governing Progressive Conservative party. Purdy also served as the mayor for the village of Wabamun for many years. Provincial politics
Purdy ran for a seat to the Alberta Legislature in the 1971 Alberta general election.
By winning the constituency he defeated incumbent Ralph Jespersen by a close margin.
He ran for a second term in the 1975 general election. The field was crowded with four opposing candidates but Purdy easily retained his seat.
He ran for a third term in the 1979 general election winning his district with a larger landslide then 1975. He ran for a fourth term in office in the 1982 general election.
Purdy retired from provincial office at dissolution of the legislature in 1986.
Municipal politics
Purdy became the mayor of the Village of Wabuman, he served in that office from at least since 2000 to 2008. He is also the current executive director for the Alberta Fire Chief"s Association.