Some remarks on regular expressions

This is a long topic, but I gather here the remarks on what I show during the lectures. You can have a look for example here



In [1]:

    
import re #Module with regular expression functionality

for match in re.findall("AC.T","TACCTACGTT"): #Look for AC then any character then T
    print(match)









    



ACCT
ACGT



In [2]:

    
for match in re.findall("AC[GA]T","TACCTACGTT"): #Look for AC then either G or A then T
    print(match)









    



ACGT



In [3]:

    
#look for "match" then space then as many characters as possible then space then "longest"
for match in re.findall("match .* longest", "match always the longest and I really mean longest string"):
    print(match)









    



match always the longest and I really mean longest



In [4]:

    
for match in re.findall("[ACGT]","ACGTYHBCGT"): #match a single character A, C, G, or T
    print(match)









    



A
C
G
T
C
G
T



In [5]:

    
for match in re.findall("[^ACGT]","ACGTYHBCGT"): #match a single character which is not A, C, G, or T
    print(match)









    



Y
H
B



In [6]:

    
print(re.sub("[^ACGT]","?","ACGTYHBCGT")) #Replace all characters which are not A,C,G,T with ?
print(re.sub("[^ACGT]","","ACGTYHBCGT")) #Remove all characters which are not A,C,G,T









    



ACGT???CGT
ACGTCGT



In [7]:

    
rexp=r"jobid: (\S+)"



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