In [20]:

    

line = """IF #CAMPO-PACK (#IDX)            =    MASK ('            'N','NN)"""


    

In [21]:

    

line = line.replace("=", "EQ")
if_old = "".join("".join(line.split("EQ")[0]).strip().split()[1:])
if_old


    

    
Out[21]:





'#CAMPO-PACK(#IDX)'

In [18]:

    

line = """                              OR=   MASK ('           'NN','NN)"""


    

In [19]:

    

line.strip().startswith("OR=")


    

    
Out[19]:





True

In [16]:

    

line.replace("OR=", "OR {} EQ".format(if_old)).strip()


    

    
Out[16]:





"OR #CAMPO-PACK EQ   MASK ('           'NN','NN)"