讀取文件中的數據混合字符串和數字在python

Question

我想在一個目錄結構如下讀取不同的文件：

# Mj = 1.60  ff = 7580.6 gg = 0.8325 

我想讀每個文件和聯繫號碼每一個到向量。 如果我們假設我有3個文件，我將有3個向量Mj的組件，... 如何在Python中執行此操作？

感謝您的幫助。

Answer 1

我會使用一個正則表達式來走線分開：

import re 
lineRE = re.compile(r''' 
    \#\s* 
    Mj\s*=\s*(?P<Mj>[-+0-9eE.]+)\s* 
    ff\s*=\s*(?P<ff>[-+0-9eE.]+)\s* 
    gg\s*=\s*(?P<gg>[-+0-9eE.]+) 
    ''', re.VERBOSE) 

for filename in filenames: 
    for line in file(filename, 'r'): 
     m = lineRE.match(line) 
     if not m: 
      continue 
     Mj = m.group('Mj') 
     ff = m.group('ff') 
     gg = m.group('gg') 
     # Put them in whatever lists you want here. 

Answer 2

這裏有一個pyparsing的解決方案，可能會更容易比一個正則表達式解決方案來管理：

text = "# Mj = 1.60  ff = 7580.6 gg = 0.8325 " 

from pyparsing import Word, nums, Literal 

# subexpression for a real number, including conversion to float 
realnum = Word(nums+"-+.E").setParseAction(lambda t:float(t[0])) 

# overall expression for the full line of data 
linepatt = (Literal("#") + "Mj" + "=" + realnum("Mj") + 
      "ff" + "=" + realnum("ff") + 
      "gg" + "=" + realnum("gg")) 

# use '==' to test for matching line pattern 
if text == linepatt: 
    res = linepatt.parseString(text) 

    # dump the matched tokens and all named results 
    print res.dump() 

    # access the Mj data field 
    print res.Mj 

    # use results names with string interpolation to print data fields 
    print "%(Mj)f %(ff)f %(gg)f" % res 

打印：

['#', 'Mj', '=', 1.6000000000000001, 'ff', '=', 7580.6000000000004, 'gg', '=', 0.83250000000000002] 
- Mj: 1.6 
- ff: 7580.6 
- gg: 0.8325 
1.6 
1.600000 7580.600000 0.832500