read and matching pattern with python I have read the content of a text file into pandas and needed some help matching the pattern.

Here is the pattern, where a can any number greater than zero and b can be zero or any number greater than zero:

father=a|0 || 0|a
mother=a|0 || 0|a
daughter1=b|0 || 0|b
daughter2=a|0 || 0|a
daughter3=b|0 || 0|b
son1=a|0 || 0|a
son2=b|0 || 0|b


Here is the function that reads the content of text file to pandas

import pandas as pd
def read():
    varian=pd.read_csv('file.txt',sep = "\t")

father=varian["FATHER"]
mother=varian["MOTHER"]
daughter1=varian["DAUGHTER1"]
daughter2=varian["DAUGHTER2"]
daughter3=varian["DAUGHTER3"]
son1=varian["SON1"]
son2=varian["SON2"]


The content of the file looks like this

HROM    POS REF ALT FATHER  MOTHER  DAUGHTER1   DAUGHTER2   DAUGHTER3   SON1    SON2    INFO    FREQUECY
1   1226852 G   C   1/0 0/0 1|0 1|0 1|0 1|0 0|0 AN=2184;AC=12   0.005494505
1   1847936 C   T   0/1 1/1 1|1 1|1 1|1 1|1 0|1 AC=1;AN=2184    0.000457875
1   2428427 C   G   0/1 0/0 0|0 0|0 0|0 0|0 1|0 AC=4;AN=2184    0.001831502
1   2515616 G   A   1/0 1/0 1/0 1|1 1|1 1/0 1/0 AC=1;AN=2184    0.000457875
1   3801895 T   C   1/0 1/0 0|0 1/0 1/0 0|0 1|1 AC=10;AN=2184   0.004578755
This is not a bioinformatics question, but a basic pandas question, so SO is a better place for this... But your odd looking VCF file can be parsed as follows without even using regex:

import pandas as pd

def splitter(cell, key):
    parts = cell.split('||')
    if key in parts[0]:
         p = parts[0].split('|')
    else:
         p = parts[1].split('|')
    sp = [x.strip() for x in p if key not in x]
    return float(sp[0])

def read():
    splitter_a = lambda v: v.split('||')[0].split('|')[1]) 
    varian=pd.read_csv('file.txt',sep = "\t")
    a_splitter = lambda c: splitter(c, 'a')
    b_splitter = lambda c: splitter(c, 'b')
    varian = varian.assign(father_a=varian.FATHER.apply(a_splitter)\
              .assign(father_a=varian.FATHER.apply(b_splitter)\
              .assign(mother_a=varian.MOTHER.apply(la_splitter)\


etc.

display(varian) or print(varian.columns) will show that you have new columns called father_a etc.