Why in sololearn and JupiterNotebook output different

Question

in file : Harry Potter
Some books
Input: file = open(".../books.txt", "r")
f = file.readlines()
for i in f:
print (i[0], len(i) - i.count('\n'), sep = '')
file.close()

Output: H12
S10
but output in sololearn: H1
a1
r1
etcetera
WTF? sorry for my English