使用带有行数的Python Regex

This is my test code:

这是我的测试代码:

\thinhline
\[-16pt]
Jacobi
  & $\JacobiP{\alpha}{\beta}{n}@{x}$
  & $(-1,1)$
  & $(1 - x)^{\alpha} (1 + x)^{\beta}$
  & $\begin{cases} \ifrac{2^{\alpha+\beta+1}\EulerGamma@{\alpha+1}\EulerGamma@{\beta+1}}{\EulerGamma@{\alpha+\beta+2}}, &\text{$n = 0$} \end{cases}$
  & $\begin{cases} \ifrac{2^{\alpha+\beta+1}\EulerGamma@{\alpha+1}\EulerGamma@{\beta+1}}{\EulerGamma@{\alpha+\beta+2}}, & \text{$n = 0$}\end{cases}$
  & $\dfrac{\pochhammer{n+\alpha+\beta+1}{n}}{2^n n!}$
  & $\dfrac{n (\alpha-\beta)}{2n+\alpha+\beta}$
  & $\alpha,\beta > -1$

  \
\thinhline
\[-16pt]
Ultraspherical(Gegenbauer)
  & $\Ultraspherical{\lambda}{n}@{x}$
  & $(-1,1)$
  & $(1 - x^2)^{\lambda-\frac{1}{2}}$
  & $\dfrac{2^{1-2\lambda} \pi \EulerGamma@{n+2\lambda}}
           {(n+\lambda) \left( \EulerGamma@{\lambda} \right)^2 n!}$
  & $\dfrac{2^n \pochhammer{\lambda}{n}}{n!}$ & 
 
 
This is my test code:
 
 
这是我的测试代码:
 
 
\thinhline
\\[-16pt]
Jacobi
  & $\JacobiP{\alpha}{\beta}{n}@{x}$
  & $(-1,1)$
  & $(1 - x)^{\alpha} (1 + x)^{\beta}$
  & $\begin{cases} \ifrac{2^{\alpha+\beta+1}\EulerGamma@{\alpha+1}\EulerGamma@{\beta+1}}{\EulerGamma@{\alpha+\beta+2}}, &\text{$n = 0$} \end{cases}$
  & $\begin{cases} \ifrac{2^{\alpha+\beta+1}\EulerGamma@{\alpha+1}\EulerGamma@{\beta+1}}{\EulerGamma@{\alpha+\beta+2}}, & \text{$n = 0$}\end{cases}$
  & $\dfrac{\pochhammer{n+\alpha+\beta+1}{n}}{2^n n!}$
  & $\dfrac{n (\alpha-\beta)}{2n+\alpha+\beta}$
  & $\alpha,\beta > -1$

  \\
\thinhline
\\[-16pt]
Ultraspherical(Gegenbauer)
  & $\Ultraspherical{\lambda}{n}@{x}$
  & $(-1,1)$
  & $(1 - x^2)^{\lambda-\frac{1}{2}}$
  & $\dfrac{2^{1-2\lambda} \pi \EulerGamma@{n+2\lambda}}
           {(n+\lambda) \left( \EulerGamma@{\lambda} \right)^2 n!}$
  & $\dfrac{2^n \pochhammer{\lambda}{n}}{n!}$ & $0$
  & $\lambda > -\tfrac{1}{2}, \lambda \ne 0 $
\\
 
 
I have created a pattern to identify the pattern of everything in between "\thinhline \\[-16pt]" and "\\". 
 
 
我创建了一个模式来识别“\thinhline \[-16pt]”和“\”之间的所有模式。
 
  
  
 
How would I find the line count of the lines beginning with ampersands, "&", of the instance of the pattern found?
 
 
我怎么能找到从ampersands开始的行数，“&”，这个模式的实例的实例呢?
 
 
For example I would want this returned for the sample code:
 
 
例如，我希望这个示例代码返回:
 
 
Jacobi: 8
Ultraspherical(Gegenbauer): 6
 
 
3 个解决方案
 
 
 
  
#1
 
  
 
  
 
   
1  
 
   
Try this regex ^\s*& with the MULTILINE (re.M) flag: 
 
   
试试这个regex ^ \ s * &多行(re.M)旗:
 
   
import re

text = """
  & $\Ultraspherical{\lambda}{n}@{x}$
  & $(-1,1)$
  & $(1 - x^2)^{\lambda-\frac{1}{2}}$
  & $\dfrac{2^{1-2\lambda} \pi \EulerGamma@{n+2\lambda}}
           {(n+\lambda) \left( \EulerGamma@{\lambda} \right)^2 n!}$
  & $\dfrac{2^n \pochhammer{\lambda}{n}}{n!}$ & $0$
  & $\lambda > -\tfrac{1}{2}, \lambda \ne 0 $

"""

print(len(re.findall('^\s*&', text, re.M)))
 
   
prints 6, which is the number of lines beginning with &
 
   
打印6，即以&开头的行数
 
  
 
 
 
 
 
  
#2
 
  
 
  
 
   
1  
 
   
How about:
 
   
如何:
 
   
import re

s = text.split('\\thinhline\n\\\\[-16pt]\n')[1:]
res = [re.split("\n\s*&", a) for a in s]

[a[0] + ": " + str(len(a)-1) for a in res]
#['Jacobi: 8', 'Ultraspherical(Gegenbauer): 6']
 
  
 
 
 
 
 
  
#3
 
  
 
  
 
   
1  
 
   
for i,line enumerate(my_text.splitlines(),1):
    if line.strip().startswith("&"):
       print line,"On line",i
 
   
might be what you want ... I dont think regex is the right answer for this
 
   
可能是你想要的……我认为regex不是正确的答案
 
  
 
 
 

$
  & $\lambda > -\tfrac{1}{2}, \lambda \ne 0 $
\
\thinhline