Research has shown that even though standardized financial education has gained prevalence to promote financial literacy over the past decade, it has had little effect on personal financial planning. The present study used a randomized control trial to examine the effectiveness of a Python-based personalized financial projection on young working adults in Hong Kong, to examine if and how this approach improves their financial planning. Participants assigned to the experiment group received standardized financial education and Python-based financial projections, while those in the control group only received standardized financial education. The assessment based on the two-wave data showed that Python-based financial projection promoted future time perspectives, reduced temporal discounting, and improved financial planning via the full mediation of promoting financial attitudes. Although numerous applications for personal financial planning exist (such as Wallet, Walnut, Monefy, and Money View), our Python-based financial projection stands out as the pioneering solution tailored for the hands-on manipulation of programming code to effectively manage personal finances. Our findings suggest a new track to upgrade personalized financial projection and standardized financial education and contribute generously to the development of personal finance education.