如何按指定单词数拆分字符串生成新变量？

按指定单词数X拆分 #

如果需要严格按设定的单词数量拆分，可以用shell脚本结合awk工具实现：

# 设定要拆分的单词数X
X=9
# 处理后的文本行，可替换为从文件读取的内容
input_line="forecast=Mostly cloudy and cooler. Precipitation possible within 12 hours, possibly heavy at times. Windy"

echo "$input_line" | awk -v split_words="$X" -F'=' '{
    split($2, word_list, / /)
    first_part = ""
    second_part = ""
    for(i=1; i<=length(word_list); i++){
        if(i <= split_words){
            first_part = first_part (first_part ? " " : "") word_list[i]
        } else {
            second_part = second_part (second_part ? " " : "") word_list[i]
        }
    }
    print "forecast=" first_part
    print "forecast2=" second_part
}'

执行后输出：

forecast=Mostly cloudy and cooler. Precipitation possible within 12 hours
forecast2=possibly heavy at times. Windy

按句号拆分（更符合语义） #

利用文本中自带的句号拆分，保证拆分后的内容语义完整，同样用awk实现：

input_line="forecast=Mostly cloudy and cooler. Precipitation possible within 12 hours, possibly heavy at times. Windy"

echo "$input_line" | awk -F'=' '{
    split($2, sentence_list, /\./)
    first_part = sentence_list[1] "."
    second_part = ""
    for(i=2; i<=length(sentence_list); i++){
        if(sentence_list[i] != ""){
            second_part = second_part (second_part ? ". " : "") sentence_list[i]
        }
    }
    if(second_part != "") second_part = second_part "."
    print "forecast=" first_part
    print "forecast2=" second_part
}'

执行后输出：

forecast=Mostly cloudy and cooler.
forecast2=Precipitation possible within 12 hours, possibly heavy at times. Windy.

Python实现方案 #

按指定单词数拆分 #

input_line = "forecast=Mostly cloudy and cooler. Precipitation possible within 12 hours, possibly heavy at times. Windy"
split_words = 9

key, content = input_line.split('=', 1)
word_list = content.split()

forecast_val = ' '.join(word_list[:split_words])
forecast2_val = ' '.join(word_list[split_words:])

print(f"forecast={forecast_val}")
print(f"forecast2={forecast2_val}")

按句号拆分 #

input_line = "forecast=Mostly cloudy and cooler. Precipitation possible within 12 hours, possibly heavy at times. Windy"

key, content = input_line.split('=', 1)
sentence_list = [s.strip() for s in content.split('.') if s.strip()]

if len(sentence_list) >= 2:
    forecast_val = f"{sentence_list[0]}."
    forecast2_val = '. '.join(sentence_list[1:]) + '.'
else:
    forecast_val = content
    forecast2_val = ""

print(f"forecast={forecast_val}")
print(f"forecast2={forecast2_val}")

内容的提问来源于stack exchange，提问作者BobW