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  1. import re
  2.  
  3. def number_atom(chemicalFormula):
  4.     abcRegex = re.compile(r'([A-Z][a-z]?)(\d*)|(\d+)|([()]{1})')
  5.     abcSearch = abcRegex.findall(chemicalFormula)
  6.     nAtom = {}
  7.     tmpList = []
  8.     inBrackets = False
  9.     for atom, quantity, multiple, brackets in abcSearch:
  10.         if brackets == '(':
  11.             inBrackets = True
  12.         elif brackets == ')':
  13.             inBrackets = False
  14.  
  15.         if inBrackets:
  16.             if atom and quantity:
  17.                 tmpList.append([atom, int(quantity)])
  18.             elif atom:
  19.                 tmpList.append([atom, 1])
  20.         elif not inBrackets and tmpList and multiple:
  21.             for a, n in tmpList:
  22.                 n *= int(multiple)
  23.                 if a in nAtom:
  24.                     nAtom[a] += n
  25.                 else:
  26.                     nAtom[a] = n
  27.             tmpList = []
  28.         else:
  29.             if atom and not quantity:
  30.                 nAtom[atom] = 1
  31.             elif atom and quantity:
  32.                 nAtom[atom] = int(quantity)
  33.  
  34.     print(chemicalFormula)
  35.     for key, value in nAtom.items():
  36.         print('{}: {}'.format(key, value))
  37.     print('------')
  38.  
  39. i = input()
  40. number_atom(i)
Success #stdin #stdout 0.02s 28384KB
comments ()
stdin
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C6H12O6
CCl2F2
NaHCO3
C4H8(OH)2
PbCl(NH3)2(COOH)2
stdout
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C6H12O6
O: 6
C: 6
H: 12
------
https://ideone.com/J1GY4X
language:
Python 3 (python  3.12)
created:
7 years ago
visibility:
public

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