A character string recognition method includes: selecting a keyword database, which corresponds to content of a character string, from a number of keyword databases, wherein the selected keyword database comprises at least one prefix keyword, comparing the content of the character string with the at least one prefix keyword, when the content of the character string corresponds to one of the at least one prefix keyword, updating the content of the character string based on a definition of the prefix keyword which corresponds to the content of the character string, and when the content of the character string does not correspond to any of the at least one prefix keyword, selectively ending the character string recognition method, and outputting the content of the character string.
Please help me write a proper abstract based on the patent claims. CLAIM: 1. A character string recognition method, comprising: selecting a keyword database, which corresponds to content of a character string, from a plurality of keyword databases, wherein the selected keyword database comprises at least one prefix keyword; comparing the content of the character string with the at least one prefix keyword; when the content of the character string corresponds to one of the at least one prefix keyword, updating the content of the character string based on a definition of the prefix keyword which corresponds to the content of the character string; and when the content of the character string does not correspond to the at least one prefix keyword, selectively ending the character string recognition method, and outputting the content of the character string. 2. The character string recognition method according to claim 1, wherein in the selected keyword database, each of the at least one prefix keyword corresponds to at least one suffix keyword, and the updating the content of the character string based on the definition of the prefix keyword which corresponds to the content of the character string comprises: comparing the content of the character string with the at least one suffix keyword; when the content of the character string corresponds to one of the at least one suffix keyword, updating the content of the character string based on a definition of the suffix keyword which corresponds to the content of the character string; and when the content of the character string does not correspond to any of the at least one suffix keyword, selectively ending the character string recognition method, and outputting the content of the character string. 3. The character string recognition method according to claim 2, wherein the comparing the content of the character string with the at least one suffix keyword comprises: starting from a character of the content of the character string, which corresponds to the prefix keyword, to determine whether each character of the character string corresponds to the at least one suffix keyword by comparison between each character of the character string and the at least one suffix keyword. 4. The character string recognition method according to claim 1, wherein in the selected keyword database, each of the at least one prefix keyword corresponds to at least one etymon keyword, and the updating the content of the character string based on the definition of the prefix keyword which corresponds to the content of the character string comprises: comparing the content of the character string with the at least one etymon keyword; when the content of the character string corresponds to one of the at least one etymon keyword, updating the content of the character string based on a definition of the etymon keyword which corresponds to the content of the character string; and when the content of the character string does not correspond to any of the at least one etymon keyword, selectively ending the character string recognition method, and outputting the content of the character string. 5. The character string recognition method according to claim 1, wherein the selecting the keyword database, which corresponds to the content of the character string, from the plurality of keyword databases comprises: searching a prefix keyword which corresponds to the content of the character string, based on one or more initial characters of the character string, from the plurality of keyword databases, in order to confirm the keyword database corresponding to the content of the character string. 6. The character string recognition method according to claim 5, wherein the selecting the keyword database corresponding to the content of the character string from the plurality of keyword databases further comprises: when no prefix keyword which corresponds to the content of the character string exists in the plurality of keyword databases, searching for a suffix keyword or an etymon keyword, which corresponds to one or more characters of the content of the character string, in the plurality of keyword databases; and based on the one or more characters and the suffix keyword or the etymon keyword, which corresponds to the one or more characters, selectively determining that at least one character previous to the one or more characters is a definition of a prefix keyword which corresponds to the suffix keyword or the etymon keyword corresponding to the one or more characters. 7. The character string recognition method according to claim 6, wherein a new prefix keyword is obtained by directing the at least one character to the definition of the prefix keyword which corresponds to the suffix keyword or the etymon keyword. 8. A machine learning method for data acquisition, comprising: the character string recognition method according to claim 1; and executing machine learning, according to the updated content of the character string, by a computer. 9. A machine learning method for data acquisition, comprising: the character string recognition method according to claim 2; and executing machine learning, according to the updated content of the character string, by a computer. 10. A machine learning method for data acquisition, comprising: the character string recognition method according to claim 3; and executing machine learning, according to the updated content of the character string, by a computer. 11. A machine learning method for data acquisition, comprising: the character string recognition method according to claim 4; and executing machine learning, according to the updated content of the character string, by a computer. 12. A machine learning method for data acquisition, comprising: the character string recognition method according to claim 5; and executing machine learning, according to the updated content of the character string, by a computer. 13. A machine learning method for data acquisition, comprising: the character string recognition method according to claim 6; and executing machine learning, according to the updated content of the character string, by a computer. 14. A machine learning method for data acquisition, comprising: the character string recognition method according to claim 7; and executing machine learning, according to the updated content of the character string, by a computer.