使用 str 数组过滤

Question

I am trying to filter an ASCII list (which contains ASCII and other characters) by using an array that I have created. I am trying to remove any integer string within the list.

import pandas as pd
with open('ASCII.txt') as f:
    data = f.read().replace('\t', ',')
    print(data, file=open('my_file.csv', 'w'))
df = list(data)
test = ['0','1','2','3','4','5','6','7','8','9']

for x in df:
    try:
        df = int(df)
        for i in range(0,9):
            while any(test) in df:
                df.remove('i') 
        print(df)
    except:
        continue

print(df)

This is what I currently have however, it does not work and outputs:

['3', '3', ',', '0', '4', '1', ',', '2', '1', ',', '!', ',', '\n', '3', '4', ',', '0', '4', ...]

Answer 1

Your if condition for numbers is broken. any checks if at least one element in the passed iterable is truthy, ie not an empty string in your case.

test = ['0','1','2','3','4','5','6','7','8','9']
while any(test) in df:  # Condition always evaluates to False
    df.remove('i')  # Only removes the character 'i' from df

So your condition any(test) evaluates to True . And now you are checking if True is in df which it isn't, so the condition evaluates to False . The next error is, that you try to remove the letter 'i' from your list with the remove call. This can be fixed by casting the integer to a string

for i in range(9):
    # Cast integer to str
    while str(i) in df:
        # Remove str i from df
        df.remove(str(i))

Using a str list instead of the range function, you can directly iterate over the elements of the test list:

df = list(data)
test = ['0','1','2','3','4','5','6','7','8','9']

for num in test:
    # Loop as long as num appears in df
    while num in df:
        df.remove(num)  # removes all elements with value of num

By doing so you have to run a second loop to remove all appearances of the current num in df , as remove only removes the first occurrence of that value.

Alternatively you can also check each element of df if it is a digit by using the str method isdigit . But as you modify the list in-place you need to iterate over a copy. Otherwise you'll encounter side-effects as you reduce the size of df :

# Use slice to create a copy of df
for el in df[:]:
    if el.isdigit():
        df.remove(el)

As you iterate over each element in df you don't need an inner loop to remove each occurrence of value el .