I have a hunch that I need to access an item in a list (of strings), modify that item (as a string), and put it back in the list in the same index
I'm having difficulty getting an item back into the same index
for item in list:
if "foo" in item:
item = replace_all(item, replaceDictionary)
list[item] = item
print item
now I get an error
TypeError: list indices must be integers, not str
due to this line list[item] = item
which makes sense! but I do not know how to put the item back into the list at that same index using python
what is the syntax for this? Ideally the for loop can keep track of the index I am currently at
For Python 3:
ListOfStrings = []
ListOfStrings.append('foo')
ListOfStrings.append('oof')
for idx, item in enumerate(ListOfStrings):
if 'foo' in item:
ListOfStrings[idx] = "bar"
You need to use the enumerate function: python docs
for place, item in enumerate(list):
if "foo" in item:
item = replace_all(item, replaceDictionary)
list[place] = item
print item
Also, it's a bad idea to use the word list as a variable, due to it being a reserved word in python.
Since you had problems with enumerate, an alternative from the itertools library:
for place, item in itertools.zip(itertools.count(0), list):
if "foo" in item:
item = replace_all(item, replaceDictionary)
list[place] = item
print item
A common idiom to change every element of a list looks like this:
for i in range(len(L)):
item = L[i]
# ... compute some result based on item ...
L[i] = result
This can be rewritten using enumerate() as:
for i, item in enumerate(L):
# ... compute some result based on item ...
L[i] = result
See enumerate.
Source: Stackoverflow.com