You can try list indexing:

data = [[6.0, 0.5], [6.1, 1.0], [6.2, 1.5], [6.3, 2.0], [6.4, 2.5], [6.5, 3.0], [6.6, 3.5], [6.7, 4.0], [6.8, 4.5]]
d1 = [item[0] for item in data]
print d1
d2 = [item[1] for item in data]
print d2

output :

[6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8]
[0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5]

You could just do:

print(friends[1])

That would give the second element, it will output:

Mark

If you want to use a loop, try:

for i, v in enumerate(friends):
    if i == 1:
        print(v)

Output:

Mark

Python indexing starts from 0, so the second element's index would be 1.

The for loop I did iterates through the list, but the iterator i is the index of every element, and v is the value, so it check if i (the index) is 1, if so, it prints v.

Printing 2 values on a list is as simple as creating a for loop that skips over every other value. When you create a for loop, you can use range(start,stop,interval) to accomplish this. Then you can just fill in the two print statements using the for loop

I hope that this will work for you:

for x in range(0,len(listtest),2):
    print (listtest[x], listtest[x+1])

replace testlist with your list's name

You missed the brackets. Try this:

p = [x[1] for x in list_of_numbers]

To print the values, you could use

print(', '.join([str(x) for x in p]))

You also need to change the way you load the data from the file

Full Code:

def parse(raw):
    data = []
    for line in raw.split("\n"):
        line = line.strip()
        # --> "('5', 2.5, 5200)"
        if line.startswith("(") and line.endswith(")"):
            d = line[line.index("(")+1 : line.index(")", -1)]
            # --> "'5', 2.5, 5200"
            d = d.split(",")
            data.append([])
            for i in d:
                i = i.strip()
                try:
                    i = float(i)
                except:
                    pass
                data[-1].append(i)
    return data


raw = open("list_of_numbers.txt").read()

list_of_numbers = parse(raw)

p = [x[1] for x in list_of_numbers]
# --> [2.5, 3.2, 5.4, 8.7]
print(', '.join([str(x) for x in p]))
# ---> 2.5, 3.2, 5.4, 8.7

I suggest using pickle. Storing and loading your data is easy as:

import pickle
data = ...
# store
file = open('data.txt', 'w')
pickle.dump(data, file)
file.close()
# load
file = open('data.txt', 'r')
data = pickle.load(file)
file.close()

That list is easily convertible to dict. The simplest approach I can think of:

In [14]: names = dict(list) # first name -> second name

In [15]: x = input('Type the first name: ')
Type the first name: Bob

In [16]: names[x] # search the `names` dictionary and return the second name
Out[16]: 'Marley'

If you don't want to convert list to dictionary, a simple loop would look like

x = input('Type the first name: ')
for first, second in list:
    if first == x:
        print(second)
        break

It can also be written as a generator expression:

In [19]: x = input('Type the first name: ')
Type the first name: Bob

In [20]: next(second for first, second in list if first == x)
Out[20]: 'Marley'

Dictionary lookups are usually faster than this and you should use the first solution if you can.

Also, try not to use names of built-in types (e.g. list) and functions as variable names.

Many way to do this. Here's a simple list way, without an explicit for loop.

tt = [[50.954818803035948, 55.49664787231189, 8007927.0, 0.0], [50.630482185654436, 55.133473852776916, 8547795.0, 0.0], [51.32738085400576, 55.118344981379266, 6600841.0, 0.0], [49.425931642638567, 55.312890225131163, 7400096.0, 0.0], [48.593467836476407, 55.073137270550006, 6001334.0, 0.0]]

print [x[2] for x in tt]

> [8007927.0, 8547795.0, 6600841.0, 7400096.0, 6001334.0]

And making is safe for potentially shorted lists

print [x[2] for x in tt if len(tt) > 3]

More sophisticated output (python 2.7), prints values as newline (\n) seperated

print '\n'.join([str(x[2]) for x in tt])

> 8007927.0
> 8547795.0
> 6600841.0
> 7400096.0
> 6001334.0

Using slice notation you can get the sublist of items you want:

>>> li = [1,2,3,4]
>>> li[2:]
[3, 4]

Then just iterate over the sublist:

>>> for item in li[2:]:
...     print item
... 
3
4

You're getting this error because you try to access the second element of an array that contains only 1 string. In this case you want to check the length of the array

for line in open("testing.txt"):
   strip = line.rstrip()
   words = strip.split(';')
   for test in words:
      if len(words) > 1:
         print(words)
      else: # this else is not necessary
         continue

Edit: If you want to print each sentences containing at least one ';' only once, you don't actually have to use a for loop. One concise way to get the desired output would be this:

for line in open("testing.txt"):
    strip = line.rstrip()
    words = strip.split(';')
    if len(words) > 1:
        print(words)