«f-strings» python code example

Example 1: python f string

"""

An f-string stands for 'function-string' it's just used to work with 
strings more appropiately, they do the exact same job as concantenating
strings but are more efficient and readable.

"""
# Concantenating strings:

Age = "25"

print("I am "+Age+" years old.")

# Using f strings:

Age = 25

print(f"I am {Age} years old.")

# ^ notice the letter 'f' at the begining of the string.
# That defines the string as being an f-string.

# A third way of inputting variables into a string is by using
# .format()

Age = "25"

print("I am {} years old.".format(Age))

# If you had more than one variable:

Age = "25"
Name = "Jeff"

print("I am {} years old, and my name is {}.".format(Age,Name))

Example 2: python f-strings

>>> name = "Fred"
>>> f"He said his name is {name!r}."
"He said his name is 'Fred'."
>>> f"He said his name is {repr(name)}."  # repr() is equivalent to !r
"He said his name is 'Fred'."
>>> width = 10
>>> precision = 4
>>> value = decimal.Decimal("12.34567")
>>> f"result: {value:{width}.{precision}}"  # nested fields
'result:      12.35'
>>> today = datetime(year=2017, month=1, day=27)
>>> f"{today:%B %d, %Y}"  # using date format specifier
'January 27, 2017'
>>> f"{today=:%B %d, %Y}" # using date format specifier and debugging
'today=January 27, 2017'
>>> number = 1024
>>> f"{number:#0x}"  # using integer format specifier
'0x400'
>>> foo = "bar"
>>> f"{ foo = }" # preserves whitespace
" foo = 'bar'"
>>> line = "The mill's closed"
>>> f"{line = }"
'line = "The mill\'s closed"'
>>> f"{line = :20}"
"line = The mill's closed   "
>>> f"{line = !r:20}"
'line = "The mill\'s closed" '