I have the following list:
l = [('15234', '8604'), ('15238', '8606'), ('15241', '8606'), ('15243', '8607')]
I would like to converted it such that the tuple values are integers and not string. How do I do that?
Desired output:
[(15234, 8604), (15238, 8606), (15241, 8606), (15243, 8607)]
What I tried so far?
l = [('15234', '8604'), ('15238', '8606'), ('15241', '8606'), ('15243', '8607')]
new_list = []
for i in `l:
new_list.append((int(i[0]), i[1]))
print(tuple(new_list))
This only converts the first element i.e. 15234, 15238, 15241, 15243 into int. I would like to convert all the values to int. How do I do that?
The easiest and most concise way is via a list comprehension:
>>> [tuple(map(int, item)) for item in l]
[(15234, 8604), (15238, 8606), (15241, 8606), (15243, 8607)]
This takes each tuple in l and maps the int function to each member of the tuple, then creates a new tuple out of them, and puts them all in a new list.
You can change the second numbers into integers the same way you did the first. Try this:
new_list.append((int(i[0]), int(i[1]))
Related
I have a list of tuples:
countries = [('Netherlands','31'),
('US','1'),
('Brazil','55'),
('Russia','7')]
Now, I want to find the index of the list, based on the first item in the tuple.
I have tried countries.index('Brazil'), I would like the output to be 2. But instead, that returns a ValueError:
ValueError: 'Brazil' is not in list
I am aware that I could convert this list into a pd DataFrame and then search for a pattern match within the first column. However, I suspect there is a faster way to do this.
You can use enumerate() to find your index:
Try:
idx = next(i for i, (v, *_) in enumerate(countries) if v == "Brazil")
print(idx)
Prints:
2
List of integer value passed through input function and then stored in a list. After which performing the operation to find the sum of all the numbers in the list
lst = list( input("Enter the list of items :") )
sum_element = 0
for i in lst:
sum_element = sum_element+int(i)
print(sum_element)
Say you want to create a list with 8 elements. By writing list(8) you do not create a list with 8 elements, instead you create the list that has the number 8 as it's only element. So you just get [8].
list() is not a Constructor (like what you might expect from other languages) but rather a 'Converter'. And list('382') will convert this string to the following list: ['3','8','2'].
So to get the input list you might want to do something like this:
my_list = []
for i in range(int(input('Length: '))):
my_list.append(int(input(f'Element {i}: ')))
and then continue with your code for summation.
A more pythonic way would be
my_list = [int(input(f'Element {i}: '))
for i in range(int(input('Length: ')))]
For adding all the elements up you could use the inbuilt sum() function:
my_list_sum = sum(my_list)
lst=map(int,input("Enter the elements with space between them: ").split())
print(sum(lst))
I have a list of data from which I need to extract the indices of some strings within that list:
str=['cat','monkey']
list=['a cat','a dog','a cow','a lot of monkeys']
I've been using re.compile to match (even partial match) individual elements of the str list to the list:
regex=re.compile(".*(monkey).*")
b=[m.group(0) for l in list for m in [regex.search(l)] if m]
>>> list.index(b[0])
3
However, when I try to iterate over the str list to find the indices of those elements, I obtain empty lists:
>>> for i in str:
... regex=re.compile(".*(i).*")
... b=[m.group(0) for l in list for m in [regex.search(l)] if m]
... print(b)
...
[]
[]
I imagine that the problem is with regex=re.compile(".*(i).*"), but I don't know how to pass the ith element as a string.
Any suggestion is very welcome, thanks!!
It looks like you need to use string formatting.
for i in str:
match_pattern = ".*({}).*".format(i)
regex = re.compile(match_pattern)
b = [m.group(0) for l in list for m in [regex.search(l)] if m]
print(b)
I'm trying to write function called toNumbers based on the following specifications:
-toNumbers modifies each entry in the list by converting it to a numeric value.
-Call toNumbers function to convert each entry in the list to numeric form.
- Display the original and converted lists in your main function, not in toNumbers
for i in (toNumbers(myList)):
myList[i] = myList [i] * (1+rate)
def main():
myList = ['5','-2','3.5','-4.5']
print(myList)
main()
However, I'm not sure what function to use in order to modify my list.
Thanks!
(I'm using Python 3.5)
rate = 0.5
input_list = ['5','-2','3.5','-4.5']
output_list = [float(item)*(1+rate) for item in input_list]
print(output_list)
Your main will look like this:
if __name__=='__main__':
new_list = [toNumbers(num) for num in myList]
print(new_list, myList)
it creates new_list by calling toNumbers on each value in the list, than returns a list of those values
then it prints both lists all in main
list = [(769.0, ), (806.0, )]
In above case, I want to print only 769, 806.
How to print tuple's from list?
I think what you are looking for is how to print the first element in list of tuples?
For a list of tuples with length 2, and you do not care about the 2nd element.
for (fp, _) in list:
print(fp)
For a list of tuples with arbitrary tuple length.
for x in list:
print(x[0])