How to acces the next value in for loop

Question

So im trying to get first letters of words(excluding first word, i already solved that) in a sentence.

But it appends spaces to the list.

Would appreciate if you help.

Here's the code:

lst = []

for t in (input()):
    if t == " ":
     lst.append(t)

print(*lst, sep="")

input1: asd dfd yjs

output1: dy

Answer 1

just this:

''.join([s[0] for s in input().split()[1:]])

step by step:

if input() returns asd dfd yjs

split string (more):

input().split() # output: ['asd', 'dfd', 'yjs']

sub list (more):

input().split()[1:] # output: ['dfd', 'yjs']

one line loop (more):

[s[0] for s in ['dfd', 'yjs']] # output: ['d', 'y']

sub string (more):

s="dfd"
s[0] # output: d

concat list of strings (more):

''.join(['d', 'y']) # output: dy

Answer 2

You may

• split your sentence into words using x.split()
• remove the first word, using a slice [1:] (from index 1 to the end)
• then keep only the first char of each word and concatenate it to a result string

x = input(">")
result = ""
for word in x.split()[1:]:
    result += word[0]
print(result)  # dy

---

Using a generator and str.join :

x = input(">")
result = ''.join(word[0] for word in x.split()[1:])

Answer 3

You're getting spaces because that's what you asked for. Read your code out loud and it will probably make sense:

if t == " ":
    lst.append(t)

If t is a space, append it to lst

Seems clear that you will only get spaces.

You want the character after t to be appended. There's two ways to do that using your for loop method: 1) if t is a space, append the next character; 2) if the previous character was a space, append t. Here's how you might implement #2:

lst = []

prev_char = None
for t in (input()):
    if prev_char == " ":
        lst.append(t)
    prev_char = t

print(*lst, sep="")

This will print the first character of ever word except the first word. Initialize last_char to a space to include the first word.

Answer 4

You could use str.split:

lst = [s[0] for s in input().split()[1:]]

Answer 5

A simple example:

lst = []
get_next = False

for t in input():
    if t == " ":
        get_next = True
    elif get_next:
        lst.append(t)
        get_next = False

print(*lst, sep="")

Answer 6

A lot great answers already and this is good case for split. If you specifically need to collect the next token after a special token in a stream of tokens, here are some other options:

inp = "asd dfd yjs"
lst = []
for a, b in zip(inp[:-1],inp[1:]):
  if a == " ":
     lst.append(b)

print(*lst, sep="")

# With comprehensions - my choice
print("".join([b for a, b in zip(inp[:-1],inp[1:]) if a == " "]))

# With functional approach
from functools import reduce
from operator import add, itemgetter

def has_prior_space(x):
  return x[0] == " "

print(reduce(add, map(itemgetter(1), filter(has_prior_space, zip(inp[:-1], inp[1:])))))

In Python 3.10, there will be a new pairwise iterator that does this type of "2 at a time" iteration specifically: zip(inp[:-1],inp[1:])

Answer 7

Use Array join():

''.join(lst)