如何使用python忽略行的某些部分？

Question

S1C(SCC1)C1=COC2C(C{OC}C3C(OC=C3)C2)C1=O

In the above string, I want the program to ignore {OC} or technically anything in between these flower brackets but work normally with rest of the string. I have a file which thousands of such strings. Some strings have more than one set of flower brackets. How should it be done?

Presently I use python 2.5 version.

Answer 1

This might help. Using regex.

import re
s = "S1C(SCC1)C1=COC2C(C{OC}C3C(OC=C3)C2)C1=O"
print re.sub("\{(.*?)\}", " ", s)   #Replacing curly brackets and its content by space. 

Output:

S1C(SCC1)C1=COC2C(C C3C(OC=C3)C2)C1=O

Answer 2

You can use string slicing for this.

Note - This will work correctly only if you have one such bracket in string

str = "S1C(SCC1)C1=COC2C(C{OC}C3C(OC=C3)C2)C1=O"

startofbracket = str.find("{")
endofbracket = str.find("}")

print str[:startofbracket]+str[endofbracket+1:]

Answer 3

You can iterate over the string and keep track of characters that are not in between brackets. The following code assumes no '{' character inside the string

string = "S1C(SCC1)C1=COC2C(C{OC}C3C(OC=C3)C2)C1=O"
output = ""
brace_found = False
for i in range(len(string)):
    if brace_found:
        if string[i] == "}":
            brace_found = False
    else:
       if string[i] != "{":
           output+=string[i]
       else:
           brace_found = True
print output
# S1C(SCC1)C1=COC2C(CC3C(OC=C3)C2)C1=O