正则表达式替换R中的某些文本

Question

I am working data.csv file and I need to process certain pattern of data. Currently, class colum in my data.csv file look like:

org.apache.camel.bam.TimeExpression.evaluate(TimeExpression.java     
org.apache.camel.bam.rules.TemporalRule.processExchange(TemporalRule.java    
org.apache.camel.bam.rules.ActivityRules.processExchange(ActivityRules.java      
org.apache.camel.bam.rules.ProcessRules.processExchange(ProcessRules.java 
org.apache.camel.bam.processor.JpaBamProcessor.processEntity(JpaBamProcessor.java    
org.apache.camel.bam.processor.JpaBamProcessor.processEntity(JpaBamProcessor.java 

Now, I need to replace text appearing before bracket "(" with text ".java". In this case, my desired output is suppose to be:

org.apache.camel.bam.TimeExpression.java     
org.apache.camel.bam.rules.TemporalRule.java     
org.apache.camel.bam.rules.ActivityRules.java    
org.apache.camel.bam.rules.ProcessRules.java
org.apache.camel.bam.processor.JpaBamProcessor.java      
org.apache.camel.bam.processor.JpaBamProcessor.java 

Currently, I am trying following code:

dscls<-gsub("\\.[^.]+($", "java", data$class)

So, basically, I am trying to find the text untill "(" and then replacing it with text ".java". But, It does not produce correct output. Can some one help me to sort out regular expression correctly?

Answer 1

We can use sub to match the word ( \\\\w+ ) followed by ( followed by another word ( \\\\w+ ) and a dot ( \\\\. ), replace it with blank ( "" ).

sub("\\w+\\(\\w+\\.", "", data$class)
#[1] "org.apache.camel.bam.TimeExpression.java"  
#[2] "org.apache.camel.bam.rules.TemporalRule.java"
#[3] "org.apache.camel.bam.rules.ActivityRules.java"      
#[4] "org.apache.camel.bam.rules.ProcessRules.java"        
#[5] "org.apache.camel.bam.processor.JpaBamProcessor.java" 
#[6]"org.apache.camel.bam.processor.JpaBamProcessor.java"

data

 data <- structure(list(class = 
 c("org.apache.camel.bam.TimeExpression.evaluate(TimeExpression.java", 
"org.apache.camel.bam.rules.TemporalRule.processExchange(TemporalRule.java", 
"org.apache.camel.bam.rules.ActivityRules.processExchange(ActivityRules.java", 
"org.apache.camel.bam.rules.ProcessRules.processExchange(ProcessRules.java", 
"org.apache.camel.bam.processor.JpaBamProcessor.processEntity(JpaBamProcessor.java", 
"org.apache.camel.bam.processor.JpaBamProcessor.processEntity(JpaBamProcessor.java"
)), .Names = "class", row.names = c(NA, -6L), class = "data.frame")

Answer 2

here df$x has the data you shared

gsub("\\w+\\(.*", "java", df$x)
[1] "org.apache.camel.bam.TimeExpression.java"           "org.apache.camel.bam.rules.TemporalRule.java"       
[3] "org.apache.camel.bam.rules.ActivityRules.java"       "org.apache.camel.bam.rules.ProcessRules.java"       
[5] "org.apache.camel.bam.processor.JpaBamProcessor.java" "org.apache.camel.bam.processor.JpaBamProcessor.java"

Answer 3

Since you already have the strings ending in .java (in example at least), you can try this too:

strs <- c('org.apache.camel.bam.TimeExpression.evaluate(TimeExpression.java','org.apache.camel.bam.rules.TemporalRule.processExchange(TemporalRule.java','org.apache.camel.bam.rules.ActivityRules.processExchange(ActivityRules.java','org.apache.camel.bam.rules.ProcessRules.processExchange(ProcessRules.java','org.apache.camel.bam.processor.JpaBamProcessor.processEntity(JpaBamProcessor.java','org.apache.camel.bam.processor.JpaBamProcessor.processEntity(JpaBamProcessor.java')

gsub('\\.\\w+\\(\\w+(\\.java)', '\\1', strs)

#[1] "org.apache.camel.bam.TimeExpression.java"           
#[2] "org.apache.camel.bam.rules.TemporalRule.java"       
#[3] "org.apache.camel.bam.rules.ActivityRules.java"      
#[4] "org.apache.camel.bam.rules.ProcessRules.java"       
#[5] "org.apache.camel.bam.processor.JpaBamProcessor.java"
#[6] "org.apache.camel.bam.processor.JpaBamProcessor.java"