如何从 python 的列表中删除某些元素？

Question

I'm scraping some data from a website but some of it is coming out with "\" in front of it. I tried to use this string of code but an error message occurred.

print([s.strip('\') for s in feet])    *EOL while scanning string literal
print([s.replace('\', ') for s in feet])

The code after the '\' in the first line became italicized, I have no clue what to do about this.

from lxml import html
import requests

list1 = []
height = []

user_website = "https://www.disabled-world.com/calculators-charts/height-weight.php"

page = requests.get(user_website)
tree = html.fromstring(page.content)
list2 = tree.xpath('//td/text()')

for x in list2:
    list_holder = x.split(" ")
    for i in list_holder:
        list1.append(i.lower())

subs = "'"
feet = [i for i in list2 if subs in i]

subs2 = '"'
inches = [i for i in list2 if subs in i]

print([s.strip('\') for s in feet])
print([s.replace('\', ') for s in feet])

y = 0

for x in feet:
    height.append(feet[y])
    height.append(inches[y])
    y+=1

print(height)

Answer 1

So I tried to extract your code, and this:

from lxml import html 
import requests 

list1 = [] 
height = [] 
user_website = "https://disabled-world.com/calculators-charts/height-weight.php" 
page = requests.get(user_website) 
tree = html.fromstring(page.content) 
list2 = tree.xpath('//td/text()')

for x in list2: 
    list_holder = x.split(" ") 
    for i in list_holder: 
        list1.append(i.lower()) 
subs = "'" 
feet = [i for i in list2 if subs in i] 
subs2 = '"' 
inches = [i for i in list2 if subs in i] 
print([s.strip('"') for s in feet]) 
#print([s.replace('\', ') for s in feet]) 
y = 0 

#for x in feet: 
#    height.append(feet[y]) 
#    height.append(inches[y]) 
#    y+=1 
#    print(height)

gives me the following output:

["4' 6", "4' 7", "4' 8", "4' 9", "4' 10", "4' 11", "5' 0", "5' 1", "5' 2", "5' 3", "5' 4", "5' 5", "5' 6", "5' 7", "5' 8", "5' 9", "5' 10", "5' 11", "6' 0", "6' 1", "6' 2", "6' 3", "6' 4", "6' 5", "6' 6", "6' 7", "6' 8", "6' 9", "6' 10", "6' 11", "7' 0"]

From your question, I assume this is what you want?

Anyway, the problem (as far as I could see) was simply wrong usage of the strip() function, which expects a string (containing the part of the source string you want to strip), not just a single character.

Answer 2

Until you post your code, it's hard to figure out the bug as to why your array is improperly formatted. However, you can use the following to fix this array:

#copy paste the data into a variable as a string using triple quotes (or convert this variable to a string)
a='''['4' 6"', '4' 6"', '4' 7"', '4' 7"', '4' 8"', '4' 8"', '4' 9"', '4' 9"', '4' 10"', '4' 10"', '4' 11"', '4' 11"', '5' 0"', '5' 0"', '5' 1"', '5' 1"', '5' 2"', '5' 2"', '5' 3"', '5' 3"', '5' 4"', '5' 4"', '5' 5"', '5' 5"', '5' 6"', '5' 6"', '5' 7"', '5' 7"', '5' 8"', '5' 8"', '5' 9"', '5' 9"', '5' 10"', '5' 10"', '5' 11"', '5' 11"', '6' 0"', '6' 0"', '6' 1"', '6' 1"', '6' 2"', '6' 2"', '6' 3"', '6' 3"', '6' 4"', '6' 4"', '6' 5"', '6' 5"', '6' 6"', '6' 6"', '6' 7"', '6' 7"', '6' 8"', '6' 8"', '6' 9"', '6' 9"', '6' 10"', '6' 10"', '6' 11"', '6' 11"', '7' 0"', '7' 0"']'''

m=a.strip('[').strip(']')  #remove braces
x=[]                       
n=m.split(',')             #creaet list of elements
for i in n:
    x.append(i.strip(" ").strip("'"))  #remove the excessive quotes and spaces
print(x)

This above code gives me x as:

['4\' 6"', '4\' 6"', '4\' 7"', '4\' 7"', '4\' 8"', '4\' 8"', '4\' 9"', '4\' 9"', '4\' 10"', '4\' 10"', '4\' 11"', '4\' 11"', '5\' 0"', '5\' 0"', '5\' 1"', '5\' 1"', '5\' 2"', '5\' 2"', '5\' 3"', '5\' 3"', '5\' 4"', '5\' 4"', '5\' 5"', '5\' 5"', '5\' 6"', '5\' 6"', '5\' 7"', '5\' 7"', '5\' 8"', '5\' 8"', '5\' 9"', '5\' 9"', '5\' 10"', '5\' 10"', '5\' 11"', '5\' 11"', '6\' 0"', '6\' 0"', '6\' 1"', '6\' 1"', '6\' 2"', '6\' 2"', '6\' 3"', '6\' 3"', '6\' 4"', '6\' 4"', '6\' 5"', '6\' 5"', '6\' 6"', '6\' 6"', '6\' 7"', '6\' 7"', '6\' 8"', '6\' 8"', '6\' 9"', '6\' 9"', '6\' 10"', '6\' 10"', '6\' 11"', '6\' 11"', '7\' 0"', '7\' 0"']