从文件返回细节，python

我有这段代码，我正在尝试计算以下内容的数量：

• .py 脚本中的代码行
• for_loops（“对于”） -while_loops（“同时”）
• if_语句（“如果”）
• 函数定义（“def”）
• 乘号（“*”
• 除号（“/”
• 加号（“+”）
• 减号（“-”）

在数学符号上，代码可以工作，但是当代码寻找 if 语句时，它返回 2，当有一个时，这是主要问题，但这让我认为我错误地编写了 for 循环，这可能会带来更多问题以后出现问题。除此之外，我不知道如何打印作者行，该行显示为 [] 而不是作者姓名

代码：

from collections import Counter
FOR_=0
WHILE_=0
IF_=0
DEF_=0
x =input("Enter file or directory: ")
print ("Enter file or directory: {0}".format(x))
print ("Filename {0:>20}".format(x))
b= open(x)
c=b.readlines()
d=b.readlines(2)
print ("Author {0:<18}".format(d))
print ("lines_of_code {0:>8}".format((len (c))))
counter = Counter(str(c))
for line in c:
    if  ("for ") in line:
        FOR_+=1
        print ("for_loops {0:>12}".format((FOR_)))
for line in c:
    if  ("while ") in line:
        WHILE_+=1
        print ("while_loops {0:>10}".format((WHILE_)))
for line in c:
    if  ("if ") in line:
        IF_+=1
        a=IF_
        print ("if_statements {0:>8}".format((a)))
for line in c:
    if  ("def ") in line:
        DEF_+=1
        print ("function_definitions {0}".format((DEF_)))
print ("multiplications {0:>6}".format((counter['*'])))
print ("divisions {0:>12}".format((counter['/'])))
print ("additions {0:>12}".format((counter['+'])))
print ("subtractions {0:>9}".format((counter['-'])))

正在读取的文件：

'''Dumbo
Author: Hector McTavish'''
    for for for  # Should count as 1 for statement
while_im_alive # Shouldn't count as a while
while blah # But this one should
  if defined # Should be an if but not a def
  def if # Should be a def but not an if
    x = (2 * 3) + 4 * 2 * 7 / 1 - 2  # Various operators

任何帮助将非常感激

不要将源代码视为字符串，而是使用ast模块来解析它，然后遍历节点：

import ast
from collections import Counter

tree = ast.parse('''
"""
Author: Nobody
"""

def foo(*args, **kwargs):
    for i in range(10):
        if i != 2**2:
            print(i * 2 * 3 * 2)

def bar():
    pass
''')

counts = Counter(node.__class__ for node in ast.walk(tree))

print('The docstring says:', repr(ast.get_docstring(tree)))
print('You have', counts[ast.Mult], 'multiplication signs.')
print('You have', counts[ast.FunctionDef], 'function definitions.')
print('You have', counts[ast.If], 'if statements.')

它非常简单，可以处理所有的极端情况：

The docstring says: 'Author: Nobody'
You have 3 multiplication signs.
You have 2 function definitions.
You have 1 if statements.