>>> st = "D=1,1;BL1=2,14;BL2=2,14;1=0,4;2=0,1;3=0,1;4=0,4;A=1,14;B=1,14;C=1,1"
>>> fragments = [s.split('=') for s in st.split(';')]
>>> d = { f[0]: f[1] for f in fragments }
>>> print(d)
{'A': '1,14', 'C': '1,1', 'B': '1,14', 'D': '1,1', 'BL1': '2,14', 'BL2': '2,14', '1': '0,4', '3': '0,1', '2': '0,1', '4': '0,4'}
>>> print(d['BL1'])
2,14
>>> print(d['1'])
0,4