Python 3: Formatted Strings
As of Python 3.6 you can use so-called "formatted strings" [or "f strings"] to easily insert variables into your strings. Just add an f in front of the string and write the variable inside curly braces [{}] like so:
>>> name = "John Doe"
>>> f"Hello {name}"
'Hello John Doe'
To split a long string to multiple lines surround the parts with parentheses [[]] or use a multi-line string [a string surrounded by three
quotes """ or ''' instead of one].
1. Solution: Parentheses
With parentheses around your strings you can even concatenate them without the need of a + sign in between:
a_str = [f"This is a line \n{str1}\n"
f"This is line 2 \n{str2}\n"
f"This is line 3"] # no variable in this line, so a leading f"" is optional but can be used to properly align all lines
Good to know: If there is no variable in a line, there is no need for a leading f for that line.
Good to know: You could archive the same result with backslashes [\] at the end of each line instead of surrounding parentheses but
accordingly to PEP8 you should prefer parentheses for line continuation:
Long lines can be broken over multiple lines by wrapping expressions in parentheses. These should be used in preference to using a backslash for line continuation.
2. Solution: Multi-Line String
In multi-line strings you don't need to explicitly insert \n, Python takes care of
that for you:
a_str = f"""This is a line
{str1}
This is line 2
{str2}
This is line 3"""
Good to know: Just make sure you align your code correctly otherwise you will have leading white space in front each line.
By the way: you shouldn't call your variable str because that's the name of the datatype itself.
Sources for formatted strings:
- What's new in Python 3.6
- PEP498
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Given pair of strings, which is multiline, perform concatenation horizontally.
Examples:
Input :
test_str1 = ”’
geeks for
geeks”’,
test_str2 = ”’
is
best”’
Output :
geeks foris
geeksbest
Explanation : 1st line joined with 1st line of 2nd string, “geeks for” -> “is”.Input :
test_str1 = ”’
geeks for ”’
test_str2 = ”’
geeks ”’
Output :
geeks for geeks
Explanation : 1st line joined with 1st line of 2nd string, “geeks for ” -> “geeks”.
Method #1 : Using zip[] + split[] + join[] + list comprehension
In this, we perform the task of splitting by “\n” using split[], and they are paired together using zip[]. The next step is joining both the zipped strings for horizontal orientation using “\n” and join[].
Python3
test_str1 =
test_str2 =
print["The original string 1 is : " + str[test_str1]]
print["The original string 2 is : " + str[test_str2]]
splt_lines = zip[test_str1.split['\n'], test_str2.split['\n']]
res = '\n'.join[[x + y for
x, y in splt_lines]]
print["After String Horizontal Concatenation : " + str[res]]
Output
The original string 1 is : geeks 4 geeks The original string 2 is : is best After String Horizontal Concatenation : geeks 4is geeksbest
Time Complexity: O[n]
Auxiliary Space: O[n]
Method #2 : Using map[] + operator.add + join[]
In this, we use map[] to with help of add[] to perform concatenation, split[] is used to perform initial split by “\n”.
Python3
from operator import add
test_str1 =
test_str2 =
print["The original string 1 is : " + str[test_str1]]
print["The original string 2 is : " + str[test_str2]]
res = '\n'.join[map[add, test_str1.split['\n'], test_str2.split['\n']]]
print["After String Horizontal Concatenation : " + str[res]]
Output
The original string 1 is : geeks 4 geeks The original string 2 is : is best After String Horizontal Concatenation : geeks 4is geeksbest
Time Complexity: O[n] -> [ join function]
Auxiliary Space: O[n]