Then you could traverse the string and, for each character, increment the corresponding counter, probably using a chained conditional.
然后你遍历整个字符串，每个字母的个数都累加到对应的计数器里面，可能会用到分支条件判断。
2
The authors advance a way to forecast the yield increment according to the recovery curve of water level and character of cranny in the carbonate aquifer, which is different from conventional methods.
提出了根据水位恢复曲线形态和含水层裂隙特征来预测井的首次酸处理效果，它与石油界所用方法有明显不同。
3
Then you could convert each character to a number (using the built-in function ord), use the number as an index into the list, and increment the appropriate counter.