Strings and print

Strings

Python allows both single- and double-quotes to be used with strings. It does not distinguish between a string and a character (like C++ does). For example:

s1 = "this is a string"
s2 = 'this is also a string'

If we look at the type, type(s1), we would see that it is a str object.

Just like C++ has a lot of functions that work on strings, python has a large library for strings. We can do:

help(str)

to see these functions.

Format strings

C++’s std::format was inspired by python and uses the same formatting. In python, we invoke the format() function on a string (it is a member function of the string class), so we can do:

a = 1
b = 2.5
c = "string"
print("a = {:2}, b = {:.3f}, c = {:10}".format(a, b, c))

but python also has f-strings which allow us to put the values directly into the { } in the format string.

print(f"a = {a:2}, b = {b:.3f}, c = {c:10}")

Important

An f-string has the form: f" ... " —with a leading f.

print

python doesn’t have a stream operator like C++’s <<. Instead we use print. By default print adds a newline, but we can suppress this by passing the end="" argument to print, e.g.:

print("this is print without a newline", end="")

see help(print) for more information.