Extracting unrecognized information from many CSV files

ex<-c("The annual observed flow rate: 99.99")

res<-regmatches(ex, regexpr("[0-9]{1,2}.[0-9]{1,2}",ex))

library(cwhmisc)
A<-cpos(ex,"rate", start=1) #position in string
res<-substr(ex, start=A+5, stop=A+9)

ex<-c("The annual observed flow rate: 99.99; the monthly flow rate: 90.03; the weekly observed flow rate: 92.22")
ndat<-unlist(strsplit(ex, "flow"))

import pandas as pd
s1=pd.DataFrame({'id':[10, 11], 'a':[1,2], 'b':[2,3], 'c':[3,4]})
s2=pd.DataFrame({'id':[10, 11, 12], 'd':[2,2, 2], 'e':[3,3, 3]})
merg = pd.merge(left=s1,right=s2,on='id').set_index('id')
print merg

    a  b  c  d  e
id               
10  1  2  3  2  3
11  2  3  4  2  3