Traversing two strings at a time python

Question

I have two strings and I want to print them one character at a time alternatively. Like say

s1 = \"Hi\"
s2 = \"Giy\"

for c,d in s1,s2:
    print c
    print         


        

Answer 1

you need to use itertools.izip_longest():

In [7]: from itertools import izip_longest

In [8]: s1="Hi"

In [9]: s2="Giy"

In [10]: "".join("".join(x) for x in izip_longest(s1,s2,fillvalue=""))
Out[10]: 'HGiiy'

or using a simple for loop:

s1="Hi"
s2="Giy"
ans=""
for i in range(min(len(s1),len(s2))):
    ans+=s1[i]+s2[i]
ans += s1[i+1:]+s2[i+1:]    
print ans                 #prints HGiiy

Answer 2

Use zip():

for c, d in zip(s1, s2):
    print c, d,

Note that this does limit the loop to the shortest of the strings.

If you need all characters, use itertools.izip_longest() instead:

from itertools import izip_longest

for c, d in izip_longest(s1, s2, fillvalue=''):
    print c, d,

Your version looped over the tuple (s1, s2), so it would print s1 first, then s2.

Answer 3

Use this function,

   def  mergeStrings(a, b):
        s = ''
        count = 0
        for i in range(min(len(a),len(b))):
            s+=a[i]
            s+=b[i]
            count+=1
        s+= a[count:] if len(a) > len(b) else b[count:]
        return s

Answer 4

Here's an explanation of why that doesn't work:

When you write:

for c, d in s1, s2:
    # ...

It means:

for c, d in [s1, s2]:
    # ...

Which is the same as:

for s in [s1, s2]:
    c, d = s
    # ../

When s is Hi, the letters get unpacked into c and d - c == 'H', d == 'i'. When you try to do the same thing with Giy, python cannot unpack it, since there are three letters but only two variables.

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As already mentioned, you want to use zip_longest