python f-string default empty value code example

Example 1: f string in python

# f-strings are short for formatted string like the following
# you can use the formatted string by two diffrent ways
# 1
name = "John Smith"
print(f"Hello, {name}")		# output = Hello, John Smith

# 2
name = "John Smith"
print("Hello, {}".format(name))		# output = Hello, John Smith

Example 2: f string repr

# If you want to use repr in f-string use "!r"
# Normal behavior (using str)
>>> color = "blue\ngreen"
>>> day = datetime.date(2020, 6, 4)
>>> f"Color is {color} and day is {day}"
'Color is blue\ngreen and day is 2020-06-04'
# Alternate behavior (using repr)
>>> f"Color is {color!r} and day is {day!r}"
"Color is 'blue\\ngreen' and day is datetime.date(2020, 6, 4)"