Law Library of Congress Chart of Laws of 157 Countries on the Extradition of Citizens
According to an explanatory blog post:
"Of the countries surveyed, 60 were found to have laws that prevent the extradition of their own citizens, while the laws of 31 other countries generally allow such requests."
"In the remaining 66 countries it appears that the extradition of a citizen may be approved in certain circumstances. For example, many require that such an extradition be provided for in a bilateral treaty with the requesting country or in an international convention signed by the countries. Other requirements may apply in different countries, or they may have a provision that simply allows a government minister to refuse the extradition of a citizen."