can you write a str.replace() using dictionary values in Python?

Question

I have to replace the north, south, etc with N S in address fields.

If I have

list = {\'NORTH\':\'N\',\'SOUTH\':\'S\',\'EAST\':\'E\',\'WEST\':\'W\'}         


        

Answer 1

def replace_values_in_string(text, args_dict):
    for key in args_dict.keys():
        text = text.replace(key, str(args_dict[key]))
    return text

Answer 2

address = "123 north anywhere street"

for word, initial in {"NORTH":"N", "SOUTH":"S" }.items():
    address = address.replace(word.lower(), initial)
print address

nice and concise and readable too.

Answer 3

All of these answers are good, but you are missing python string substitution - it's simple and quick, but requires your string to be formatted correctly.

address = "123 %(direction)s anywhere street"
print(address % {"direction": "N"})

Answer 4

I would suggest to use a regular expression instead of a simple replace. With a replace you have the risk that subparts of words are replaced which is maybe not what you want.

import json
import re

with open('filePath.txt') as f:
   data = f.read()

with open('filePath.json') as f:
   glossar = json.load(f)

for word, initial in glossar.items():
   data = re.sub(r'\b' + word + r'\b', initial, data)

print(data)

Answer 5

Both using replace() and format() are not so precise:

data =  '{content} {address}'
for k,v in {"{content}":"some {address}", "{address}":"New York" }.items():
    data = data.replace(k,v)
# results: some New York New York

'{ {content} {address}'.format(**{'content':'str1', 'address':'str2'})
# results: ValueError: unexpected '{' in field name

It is better to translate with re.sub() if you need precise place:

import re
def translate(text, kw, ignore_case=False):
    search_keys = map(lambda x:re.escape(x), kw.keys())
    if ignore_case:
        kw = {k.lower():kw[k] for k in kw}
        regex = re.compile('|'.join(search_keys), re.IGNORECASE)
        res = regex.sub( lambda m:kw[m.group().lower()], text)
    else:
        regex = re.compile('|'.join(search_keys))
        res = regex.sub( lambda m:kw[m.group()], text)

    return res

#'score: 99.5% name:%(name)s' %{'name':'foo'}
res = translate( 'score: 99.5% name:{name}', {'{name}':'foo'})
print(res)

res = translate( 'score: 99.5% name:{NAME}', {'{name}':'foo'}, ignore_case=True)
print(res)

Answer 6

"Translating" a string with a dictionary is a very common requirement. I propose a function that you might want to keep in your toolkit:

def translate(text, conversion_dict, before=None):
    """
    Translate words from a text using a conversion dictionary

    Arguments:
        text: the text to be translated
        conversion_dict: the conversion dictionary
        before: a function to transform the input
        (by default it will to a lowercase)
    """
    # if empty:
    if not text: return text
    # preliminary transformation:
    before = before or str.lower
    t = before(text)
    for key, value in conversion_dict.items():
        t = t.replace(key, value)
    return t

Then you can write:

>>> a = {'hello':'bonjour', 'world':'tout-le-monde'}
>>> translate('hello world', a)
'bonjour tout-le-monde'