Python，如何替换列表中元素的多个部分（列表中）

Question

A list of original strings:

Originals = ["nice apple", "orange", "pear sweet", "red ape"]

A list of strings to remove:

To_remove = ["nice ", " sweet"]

What I want to achieve is to remove the strings needed to be removed in each elements in the original words

result: ["apple", "orange", "pear", "red ape"]

I do following but it doesn't produce a good result.

for t in To_remove:
    for o in Originals:
        print o.replace(t, "")

what would be the right way? Thank you.

Answer 1

Because string is immutable, you have to reassign the list element.

for t in To_remove:
    for i, o in enumerate(Originals):
        Originals[i] = o.replace(t, "")

print Originals 

hope this helps.

Answer 2

Strings are immutable. Hence, none of the methods you can call on a string does an in-place modification. They all return a new string, so you have to reassign the string returned by replace :

for t in To_remove:
    for i in range(len(Originals)):
        Originals[i] = Originals[i].replace(t, "")

You can check out this question for how to merge the replacement of multiple patterns.

Answer 3

You are printing the results of the replacement, but do not change the list contents. If you have a closer look on the replace method (for string s(!)), you'll see that you are not only not changing the list but also not changing the strings you are getting for o in Originals . I omit including a working example, since schwobaseggl and thangtn ^[1] already provide it.

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^[1] Who was really first? The SO timestamps contradict my personal experience.

Answer 4

Originals = ["nice apple", "orange", "pear sweet", "red ape"]
To_remove = ["nice ", " sweet"]
result = []

for o in Originals:
    for t in To_remove:
        result.append(o.replace(t, ""))

print result

Is that what you need?