Could you please share what you've tried and what is your code ?

I assume you took python module pairwise2

You can take a look at the format_alignment function and rewrite your own, something like this

def my_format_alignment(align1, align2, score, begin, end): 
    s = [] 
    s.append("%s\n" % align1) 
    s.append(" " * begin) 
    gap=0
    mismatch=0
    for a, b in zip(align1[begin:end], align2[begin:end]): 
        if a == b: 
            s.append("|")  # match 
        elif a == "-" or b == "-": 
            s.append(" ")  # gap
            gap+=1
        else: 
            s.append(".")  # mismatch 
            mismatch+=1
    s.append("\n") 
    s.append("%s\n" % align2) 
    s.append("  Score=%g\n" % score)
    s.append("  Gap=%g\n" % gap)
    s.append("  Mismatch=%g\n" % mismatch)
    return ''.join(s) 

from Bio import pairwise2
alignments = pairwise2.align.globalxx("ACCGT", "ACG")
from Bio.pairwise2 import format_alignment
print(format_alignment(*alignments[0]))
#ACCGT
#| || 
#A-CG-
#  Score=3
print(my_format_alignment(*alignments[0]))
#ACCGT
#| || 
#A-CG-
#  Score=3
#  Gap=2
#  Mismatch=0