How to replace part of the values in the list using the values from the dictionary?-CodePudding

The following method can only replace one value:

my_list = ['apple', 'pear', 'grape', 'banana', 'kiwi', 'plum']
my_list = list(map(lambda x: x.replace('apple','strawberry'), my_list))
print(my_list)

['strawberry', 'pear', 'grape', 'banana', 'kiwi', 'plum']

I wanted to try adding a dictionary instead of a pair of values ("old","new"):

my_list = list(map(lambda x: x.replace({'apple':'strawberry', 'banana':'raspberry'}), my_list))

But an error message appears: "replace() takes at least 2 arguments (1 given)"

CodePudding user response：

You can do like this,

d = {"apple": "strawberry", "banana": "raspberry"}
out = list(map(lambda x: d.get(x, x), my_list))

# Output
# ['strawberry', 'pear', 'grape', 'raspberry', 'kiwi', 'plum']

CodePudding user response：

Since replace is returning a string you can call it again, try this:

my_list = ['apple', 'pear', 'grape', 'banana', 'kiwi', 'plum']
my_list = list(map(lambda x: x.replace('apple','strawberry').replace("banana", "raspberry"), my_list))
print(my_list)

If you have a lot of key:value-pairs you might want to use functools.reduce

from functools import reduce
replacements = ('apple','strawberry'), ("banana", "raspberry")
my_list = [reduce(lambda a, kv: a.replace(*kv), replacements, x) for x in my_list]
print(my_list)