python f string - ghdrako/doc_snipets GitHub Wiki

task_f = f"Name: {name}; Urgency Level: {urgency}"
assert task == task_f == "Name: Homework; Urgency Level: 5"

Interpolates a list object

tasks = ["homework", "laundry"]
assert f"Tasks: {tasks}" == "Tasks: ['homework', 'laundry']"

Interpolates a tuple object

task_hwk = ("Homework", "Complete physics work")
assert f"Task: {task_hwk}" == "Task: ('Homework', 'Complete physics work')"

Interpolates a dict object

task = {"name": "Laundry", "urgency": 3}
assert f"Task: {task}" == "Task: {'name': 'Laundry', 'urgency': 3}"

f-strings to interpolate expressions

Accesses an item in the list

tasks = ["homework", "laundry", "grocery shopping"]
assert f"First Task: {tasks[0]}" == 'First Task: homework'

Calls a function

task_name = "grocery shopping"
assert f"Task Name: {task_name.title()}" == 'Task Name: Grocery Shopping'

Direct calculation

number = 5
assert f"Square: {number*number}" == 'Square: 25'

format specifier

task_ids = [1, 2, 3]
task_names = ['Do homework', 'Laundry', 'Pay bills']
task_urgencies = [5, 3, 4]
for i in range(3):
print(f'{task_ids[i]:^12}{task_names[i]:^12}{task_urgencies[i]:^12}')

# Output the following lines:
           1 Do homework         5
           2 Laundry             3 
           3 Pay bills           4

def create_formatted_records(fmt):
  for i in range(3):
    task_id = task_ids[i]
    name = task_names[i]
    urgency = task_urgencies[i]
    print(f'{task_id:{fmt}}{name:{fmt}}{urgency:{fmt}}')

create_formatted_records('^15')

create_formatted_records('^18')

F-string	Output	Description
f"{task:*>10}" a	"**homework"	Right alignment, * as padding
f"{task:*<10}"	"homework**"	Left alignment, * as padding
f"{task:*^10}"	"homework"	Center alignment, * as padding
f"{task:^10}" "	homework "	Center alignment, space as padding

Numeric type	F-string	Output	Description
int	f"{number:b}" "1111"	Binary format, using base 2
int	f"{number:c}"	"\x0f"	Unicode representation of the integer
int	f"{number:d}"	"15"	Decimal format, using base 10
int	f"{number:o}"	"17"	Octal format, using base 8
int	f"{number:x}"	"f"	Hexadecimal format, using base 16
float	f"{point:.2e}"	"1.23e+00"	Scientific notation
float	f"{point:.2f}"	"1.23"	Fixed-point notation with two-digit precision
float	f"{point:.2g}"	"1.23"	General format, automatically applying e or f
float	f"{point:.2%}"	"123.45%"	Percentage with two-digit precision

pct_number = 0.179323
print(f"Percentage: {pct_number:%}")
# output: Percentage: 17.932300%
print(f"Percentage two digits: {pct_number:.2%}")
# output: Percentage two digits: 17.93%