Adding values from loop to a tuple results in nested tuples instead of a flat tuple or list
Question:
I’m trying to perform the following:
tup1 = ()
for i in range(1, 10, 2):
tup1 = (tup1, i)
print tup1
I expect the output to be the sequence 1 to 10.
However, I end up with the following:
((((((), 0), 2), 4), 6), 8)
What would be a correct way to meet the requirement?
Answers:
it’s something like this:
print range(1, 11)
Tuples are immutable objects in Python. Thus means you can’t modify them. What you’re doing right now is creating a new tuple with the previous one inside
You could do:
lst = []
for i in range(1,10,2):
lst.append(i)
tup = tuple(lst) #If you really want a tuple
print tup
But lst = range(1,10,2) or tup = tuple(range(1,10,2)) is much better (Unless you want to use append for some reason)
If you just want an iterable with the even numbers 1 to 10 then the simplest way to do it:
seq = range(2, 11, 2)
If you are doing this as a means of learning Python and you want to build up your own data structure, use a list:
l = []
for i in range(2, 11, 2):
l.append(i)
The above for loop can be rewritten as a list comprehension:
l = [i for i in range(2, 11, 2)]
or using an if clause in the loop comprehension:
l = [ i for i in range(1, 11) if i % 2 == 0]
You can append an item to a tuple using the += operator.
tup1=()
for i in range(1,10,2):
tup1+= (i,)
print tup1
This prints (1, 3, 5, 7, 9)
Read about List Comprehension
tuple(i for i in range(1, 10, 2))
Or
tup1 = ()
for i in range(1, 10, 2):
tup1 += (i,)
print tup1
You are skipping by two by using for i in range(1,10,2): if you use for i in range(1,11): if will increment by 1. As for tup1=(tup1,i) you are constantly adding a tuple to each other which is creating the weird output. You could use a list if you want to store them. Otherwise using will do it just fine:
print(range(10))
List item
For appending into list or tuple you can use append() function or you can use += operator which does the same.
s=()
for sequence of numbers from 1 to 10
for i in range(1,11):
s+=(i,)
print(s) #(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
for sequence of numbers from 1 to 10 with step size 2
x=()
for i in range(1,11,2):
x+=(i,)
print(x) #odd nos from 1-9 (1, 3, 5, 7, 9)
x=()
for i in range(2,11,2):
x+=(i,)
print(x) #even nos from 2-10 (2, 4, 6, 8, 10)
- List item
Storing values from loop in a list or tuple in Python by following ways –
-> By appending the value in the list (here new_data1) as join will not work here.
new_data1 = []
for line in all_words:
new_data=' '.join(lemmatize_sentence(line))
new_data1.append(new_data)
#print (new_data)
print (new_data1)
P.S. – This is just a snapshot of a code just for hint .
Hope this helps!!
I’m trying to perform the following:
tup1 = ()
for i in range(1, 10, 2):
tup1 = (tup1, i)
print tup1
I expect the output to be the sequence 1 to 10.
However, I end up with the following:
((((((), 0), 2), 4), 6), 8)
What would be a correct way to meet the requirement?
it’s something like this:
print range(1, 11)
Tuples are immutable objects in Python. Thus means you can’t modify them. What you’re doing right now is creating a new tuple with the previous one inside
You could do:
lst = []
for i in range(1,10,2):
lst.append(i)
tup = tuple(lst) #If you really want a tuple
print tup
But lst = range(1,10,2) or tup = tuple(range(1,10,2)) is much better (Unless you want to use append for some reason)
If you just want an iterable with the even numbers 1 to 10 then the simplest way to do it:
seq = range(2, 11, 2)
If you are doing this as a means of learning Python and you want to build up your own data structure, use a list:
l = []
for i in range(2, 11, 2):
l.append(i)
The above for loop can be rewritten as a list comprehension:
l = [i for i in range(2, 11, 2)]
or using an if clause in the loop comprehension:
l = [ i for i in range(1, 11) if i % 2 == 0]
You can append an item to a tuple using the += operator.
tup1=()
for i in range(1,10,2):
tup1+= (i,)
print tup1
This prints (1, 3, 5, 7, 9)
Read about List Comprehension
tuple(i for i in range(1, 10, 2))
Or
tup1 = ()
for i in range(1, 10, 2):
tup1 += (i,)
print tup1
You are skipping by two by using for i in range(1,10,2): if you use for i in range(1,11): if will increment by 1. As for tup1=(tup1,i) you are constantly adding a tuple to each other which is creating the weird output. You could use a list if you want to store them. Otherwise using will do it just fine:
print(range(10))
List item
For appending into list or tuple you can use append() function or you can use += operator which does the same.
s=()
for sequence of numbers from 1 to 10
for i in range(1,11):
s+=(i,)
print(s) #(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
for sequence of numbers from 1 to 10 with step size 2
x=()
for i in range(1,11,2):
x+=(i,)
print(x) #odd nos from 1-9 (1, 3, 5, 7, 9)
x=()
for i in range(2,11,2):
x+=(i,)
print(x) #even nos from 2-10 (2, 4, 6, 8, 10)
- List item
Storing values from loop in a list or tuple in Python by following ways –
-> By appending the value in the list (here new_data1) as join will not work here.
new_data1 = []
for line in all_words:
new_data=' '.join(lemmatize_sentence(line))
new_data1.append(new_data)
#print (new_data)
print (new_data1)
P.S. – This is just a snapshot of a code just for hint .
Hope this helps!!