Low-altitude economy term frequency

Use Python and Jieba word segmentation tool to process TXT format annual report text. Combining the Implementation of Innovative Applications in General Aviation Equipment The policy document "Plan (2024-2030)" includes the construction of low altitude, airspace, unmanned aerial vehicles eVTOL、 Vertical takeoff and landing A low altitude economic dictionary with 12 keywords: aviation, airport, remote sensing technology, avionics, satellite, navigation, and Beidou. Translate this word into English Import Jieba's proprietary dictionary module into the dictionary, perform word segmentation and frequency statistics on the text of enterprise annual reports, and calculate the above relationships for each company The total frequency of occurrence of key words. It should be noted that although the word frequency statistics can be traced back to 2014. However, in data cleaning, due to a large number of missing key variables before 2018, forcibly including early samples will result in serious sample loss and cannot form a balanced panel. To ensure the completeness of the regression samples and the comparability of the estimation results, this study will ultimately set the research window uniformly to 690 A-share listed companies with the best data conditions from 2019 to 2023.