How can I find where a string is in a list?

Question

I want to set a variable to a certain value in a list. I need to find where the specific string is in the list without knowing what the contents of the list will be.
For instance:

list = ["a", "b", "c"]
valueIWantToFind = "b"

# code that finds where value is


variable = list.1

I thought of doing a for loop, but I don’t know how to get the current value of the list to compare it to the value I want to find.

Some thing like this:

for x in list:
 if(valueIWantToFind == currentValueOfList):
   variable = currentValueOfList
 else:
   continue

Asked By: AeroGlory

||

Source

Answer 1

I would use a list comprehension with an if condition

my_list = ["a", "b", "c"]

value_i_want_to_find = "b"

idx_list = [i for i, el in enumerate(my_list) if el == value_i_want_to_find]

You’ll have a list of indices where the element equals value_i_want_to_find.

Answered By: Seb

Answer 2

"I need to find where the specific string is in the list without knowing what the contents of the list will be".

For this you would use the index() function of a list but also take into account that if what you’re looking for doesn’t exist you’ll get an exception.

For example:

list_ = ['a', 'b', 'c']
try:
  idx = list_.index('b')
  print(f'Found at index {idx}')
  idx = list_.index('z')
  print(f'Found at index {idx}') # this won't happen
except ValueError:
  print('Not found') # this will happen when we search for 'z'

Output:

Found at index 1
Not found

Answered By: CtrlZ

How can I find where a string is in a list?

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