Python 检查字符串是否有字符

Question

I am processing 500GB of data to find only the lines which has Characters. Can you suggest me a efficent/Faster way.

Data is like:
%^^%^^%^^%
This is a valid 
*%^%^ Valid
This is not a valid one

output should be:

Data is like:
This is a valid 
*%^%^ Valid
This is not a valid one

I am trying this: isalpha() issue is it will remoce the line *%^%^ Valid

Actuall some how this code is also not working

if line.isalpha()=='True':
  print(line)

This is not working...

can I use regular expressions but read some where it will slow it is that true?

Answer 1

Use regex, like:

>>> import re
>>>
>>> pattern = re.compile(r'\A[%|\^]*$')
>>>
>>> pattern.match('%^ Text')  # no match
>>> pattern.match('%^^%^')  # match
<re.Match object; span=(0, 5), match='%^^%^'>

Answer 2

You are not using isalpha correctly, it returns True when all characters in the string are alphabetic.

You could try using any and map to make sure at least one character is alphabet in the line.

txt = """
Data is like:
%^^%^^%^^%
This is a valid 
*%^%^ Valid
This is not a valid one
"""

for line in txt.split("\n"):
    if any(map(str.isalpha, line)):
        print(line)

prints:

Data is like:
This is a valid 
*%^%^ Valid
This is not a valid one