正則表達式來排除串並表達

Question

內屬性我有一個正則表達式，這將{{ expression }}轉換成{% print expression %}時表達{{ function() }}或{{ object.function() }}或類似{{ a+b }}算術運算，但不會轉換時，它會得到{{ var }}或{{ object.attribute }}。

用正則表達式我的問題是轉換字符串表達式{{ "string" }}或{{ "function()" }}或{{ "{{ var}}" }}到{% print "string" %}或{% print "function()" %}或{% print "{% print var %}" %}

import re 

def replacement(val): 
    content = val.group(1) 
    if re.match('^\s*[\w\.]+\s*$', content): 
     return "{{%s}}" % content 
    else: 
     return "{%% print %s %%}" % content 

string_obj = """{{ var }} {{ object.var }} {{ func()}} {{ object.function() }} {{ a+b }} {{ "string" }} {{ "{{ var }}" }} {{ "function()" }} {{ "a+b" }}""" 

print(re.sub("{{(\s*.*?\s*)}}", replacement, string_obj)) 

輸出：

「{{VAR}} {{對象。％} {％print「string」％} {％print「{{var}}」％％{} print {％printf {％} {％print object.function（）％} {％print a + b％ } {％print 「function（）」％} {％p RINT 「A + B」 ％} '

我想要的輸出是：

'{{VAR}} {{object.var}} {％打印FUNC（）％} { ％print object.function（）％} {％print a + b％} {{「string」}} {{「{{var}}」}} {{「function（）」 }} {{「a + b」}}」

注：這裏的一個條件是在{{ }}之間可以具有像字符串表達式表達即用雙引號或{{ 'string' }}即用單引號。

Answer 1

代碼

對於更漂亮的打印，我只是在開始和結束時剝去空白。它也簡化了正則表達式。

import re 

def replacement(val): 
    content = val.group(1).strip() 
    if re.match('^\w[^\.\(\+\*\/\-\|]*\.?\w[^\.\(\+\*\/\-\|]*$', content): 
     return "{{ %s }}" % content 
    else: 
     return "{%% print %s %%}" % content 

def maskString(templateString): 
    stringChars = ['"', "'"] 
    a = 0 
    start = None 
    maskedList = [] 
    while a < len(templateString): 
     l = templateString[a] 
     if l in stringChars and start is None and a-1 >=0 and templateString[a-1] != '\\': 
      start = {'l' : l, 's' : a} 
     elif start is not None and l is start['l'] and a-1 >=0 and templateString[a-1] != '\\': 
      start['e'] = a + 1 
      stringToMask = templateString[start['s']:start['e']] 
      templateString = templateString[:start['s']] + ("_" * len(stringToMask)) + templateString[start['e']:] 
      maskedList.append(stringToMask) 
      start = None 
     a += 1 
    return (templateString, maskedList) 

def unmaskString(templateString, maskedList): 
    for string in maskedList: 
     templateString = templateString.replace("_" * len(string), string,1) 
    return templateString 

def templateMatcher(templateString): 
    p = re.compile('("[^"]*)"') 
    templateString, maskedList = maskString(templateString) 
    templateString = re.sub("{{(\s*.*?\s*)}}", replacement, templateString) 
    return unmaskString(templateString, maskedList) 

string_obj = """{{ var }} {{ object.var }} {{ func()}} {{ object.function() }} {{ a+b }} {{ "string" }} {{ "{{ var }}" }} {{ "function()" }} {{ "a+b" }}""" 
string_obj_2 = """{{ a+b*c-d/100}} {{ 1 * 2 }} {{ 20/10 }} {{ 5-4 }}""" 
string_obj_3 = """{{ "another {{ mask" }} {{ func() }}, {{ a+b }} , {{ "string with \\""|filter }}""" 

print(templateMatcher(string_obj)) 
print(templateMatcher(string_obj_2)) 
print(templateMatcher(string_obj_3)) 

新增了先進的屏蔽爲字符串，這樣"\""和'"'將被識別爲字符串，假設變量不可能只由_。字符串的開始和結束字符在變量stringChars中。所以如果你不喜歡'只是從那裏刪除它。

輸出

{{ var }} {{ object.var }} {% print func() %} {% print object.function() %} {% print a+b %} {{ "string" }} {{ "{{ var }}" }} {{ "function()" }} {{ "a+b" }} 
{% print a+b*c-d/100 %} {% print 1 * 2 %} {% print 20/10 %} {% print 5-4 %} 
{{ "another {{ mask" }} {% print func() %}, {% print a+b %} , {% print "string with \""|filter %}