I would like my program to print every other letter in the string "welcome". like:
e
c
m
Here is the code I have so far:
stringVar = "welcome"
countInt = 7
count = 0
oneVar = 1
twoVar = 2
showVar = stringVar[oneVar:twoVar]
for count in range(countInt):
count = count + 1
oneVar = oneVar + count
twoVar = twoVar + count
print(showVar)
Though it only shows the 2nd letter "e". How can I get the variables oneVar and twoVar to update so that the range changes for the duration of the loop?
There is a built in notation for this, called "slicing":
>>> stringVar = "welcome"
>>> print(stringVar[::2])
wloe
>>> print(stringVar[1::2])
ecm
stringVar is iterable like a list, so the notation means [start : end : step]. Leaving any one of those blank implicitly assumes from [0 : len(stringVar) : 1]. For more detail, read the linked post.
Another more complex way of the doing the same would be
string_var = "welcome"
for index, character in enumerate(string_var, start=1): # 'enumerate' provides us with an index for the string and 'start' allows us to modify the starting index.
if index%2 == 0:
print character
Why its not working in your snipet:
Even though you increase oneVar and twoVar inside the loop, there is no change in the showVar as showVar is string which is immutable type, and its printing stringVar[1:2] which is e the 2nd index of welcome:
Just to fix your snippet: You can just try like this;
stringVar = "welcome"
countInt = 7
for count in range(1,countInt,2):
print count, stringVar[count]
Output:
e
c
m
e c m