*Memos:
- My post explains Format Specification with format() (1).
- My post explains Format Specification with format() (2).
- My post explains Format Specification with format() (3).
- My post explains Format Specification with format() (4).
- My post explains Format Specification with format() (5).
- My post explains format().
- My post explains format_map().
- My post explains a string.
f-strings can format a string as shown below. *Format Specification can be used with f-strings:
*Memos:
-
forFwith''or""must be used.
<{variable}>:
*Memos:
- A
{}can output a value. - A
{}must have an expression with zero or more spaces. - A
{}can have=with zero or more spaces after an expression to output the value including its expression. - If using
=, the spaces in the expression and around=in{}are included in the value. - If not using
=, the spaces in the expression in{}aren't included in the value.
v1 = 'A'
v2 = 'B'
v3 = 'C'
print(f'-{v1}-{v2}-{v3}-')
print(F"-{v1}-{v2}-{v3}-")
print(f'-{ v1 }-{ v2 }-{ v3 }-')
print(F"-{ v1 }-{ v2 }-{ v3 }-")
# -A-B-C-
print(f'-{v1=}-{v2=}-{v3=}-')
print(F"-{v1=}-{v2=}-{v3=}-")
# -v1='A'-v2='B'-v3='C'-
# ↓ ↓ ↓ ↓↓ ↓↓ ↓↓ ↓↓↓↓ ↓↓↓↓ ↓↓↓↓
print(f'-{ v1 = }-{ v2 = }-{ v3 = }-')
print(F"-{ v1 = }-{ v2 = }-{ v3 = }-")
# - v1 = 'A'- v2 = 'B'- v3 = 'C'-
# ↑ ↑ ↑ ↑↑ ↑↑ ↑↑ ↑↑↑↑ ↑↑↑↑ ↑↑↑↑
print(f'{'ABC'} {100} {True}')
print(F"{'ABC'} {100} {True}")
# ABC 100 True
print(f'')
print(F"")
# Nothing
print(f'{}')
print(F"{}")
print(f'{ }')
print(F"{ }")
# SyntaxError: f-string: valid expression required before '}'
v1 = 'AB'
v2 = 4
print(f'-{v1+'CDE'}-{3*v2}-')
print(f'-{ v1 + 'CDE' }-{ 3 * v2 }-')
print(f'-{ v1 + 'CDE' }-{ 3 * v2 }-')
print(f'-{ v1 + 'CDE' }-{ 3 * v2 }-')
# -ABCDE-12-
print(f'-{v1+'CDE'=}-{3*v2=}-')
# -v1+'CDE'='ABCDE'-3*v2=12-
# ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓
print(f'-{ v1 + 'CDE' = }-{ 3 * v2 = }-')
# - v1 + 'CDE' = 'ABCDE'- 3 * v2 = 12-
# ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑
# ↓↓ ↓↓ ↓↓ ↓↓ ↓↓ ↓↓ ↓↓ ↓↓ ↓↓ ↓↓
print(f'-{ v1 + 'CDE' = }-{ 3 * v2 = }-')
# - v1 + 'CDE' = 'ABCDE'- 3 * v2 = 12-
# ↑↑ ↑↑ ↑↑ ↑↑ ↑↑ ↑↑ ↑↑ ↑↑ ↑↑ ↑↑
# ↓↓↓↓ ↓↓↓↓ ↓↓↓↓ ↓↓↓↓ ↓↓↓↓ ↓↓↓↓ ↓↓↓↓ ↓↓↓↓ ↓↓↓↓ ↓↓↓↓
print(f'-{ v1 + 'CDE' = }-{ 3 * v2 = }-')
# - v1 + 'CDE' = 'ABCDE'- 3 * v2 = 12-
# ↑↑↑↑ ↑↑↑↑ ↑↑↑↑ ↑↑↑↑ ↑↑↑↑ ↑↑↑↑ ↑↑↑↑ ↑↑↑↑ ↑↑↑↑ ↑↑↑↑
print(f'-{'AB'+'CDE'}-{3*4}-')
print(f'-{ 'AB' + 'CDE' }-{ 3 * 4 }-')
print(f'-{ 'AB' + 'CDE' }-{ 3 * 4 }-')
print(f'-{ 'AB' + 'CDE' }-{ 3 * 4 }-')
# -ABCDE-12-
print(f'-{'AB'+'CDE'=}-{3*4=}-')
# -'AB'+'CDE'='ABCDE'-3*4=12-
# ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓
print(f'-{ 'AB' + 'CDE' = }-{ 3 * 4 = }-')
# - 'AB' + 'CDE' = 'ABCDE'- 3 * 4 = 12-
# ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑
# ↓↓ ↓↓ ↓↓ ↓↓ ↓↓ ↓↓ ↓↓ ↓↓ ↓↓ ↓↓
print(f'-{ 'AB' + 'CDE' = }-{ 3 * 4 = }-')
# - 'AB' + 'CDE' = 'ABCDE'- 3 * 4 = 12-
# ↑↑ ↑↑ ↑↑ ↑↑ ↑↑ ↑↑ ↑↑ ↑↑ ↑↑ ↑↑
# ↓↓↓↓ ↓↓↓↓ ↓↓↓↓ ↓↓↓↓ ↓↓↓↓ ↓↓↓↓ ↓↓↓↓ ↓↓↓↓ ↓↓↓↓ ↓↓↓↓
print(f'-{ 'AB' + 'CDE' = }-{ 3 * 4 = }-')
# - 'AB' + 'CDE' = 'ABCDE'- 3 * 4 = 12-
# ↑↑↑↑ ↑↑↑↑ ↑↑↑↑ ↑↑↑↑ ↑↑↑↑ ↑↑↑↑ ↑↑↑↑ ↑↑↑↑ ↑↑↑↑ ↑↑↑↑
*Indentation is possible between { and }.
v = 'CD'
print(f'AB{
v + 'EF'}')
print(f'AB{v
+ 'EF'}')
print(f'AB{v +
'EF'}')
print(f'AB{v + 'EF'
}')
# ABCDEF
print(f'
AB{v + 'EF'}')
print(f'AB
{v + 'EF'}')
print(f'AB{v + 'EF'}
')
# SyntaxError: unterminated f-string literal
*Format Specification can be used with f-strings as I explain it with f-strings in my post:
v = -0.0
print(f'"{v:0>-z#010_.0f}"')
print(f'"{v:0>-z#10_.0f}"')
print(f'"{v:>-z#010_.0f}"')
# "000000000."
print(f'"{v:0>-z#010_.0f}" "{v:0>-z#10_.0f}" "{v:>-z#010_.0f}"')
print(f'"{v:0>-z#010_.0f}" "{v:0>-z#10_.0f}" "{v:>-z#010_.0f}"')
# "000000000." "000000000." "000000000."
<{variable[index]}>:
v = ['A', 'B', 'C']
print(f'-{v}-{v[0]}-{v[1]}-{v[2]}-')
# -['A', 'B', 'C']-A-B-C-
v = [['A', 'B'], ['C', 'D']]
print(f'-{v}\n-{v[0]}-{v[1]}\n-{v[0][0]}-{v[0][1]}-{v[1][0]}-{v[1][1]}-')
# -[['A', 'B'], ['C', 'D']]
# -['A', 'B']-['C', 'D']
# -A-B-C-D-
<{variable[key]}>:
*key cannot omit "" or ''.
v = {'name':'John', 'age':36}
print(f'-{v}\n-{v['name']}-{v['age']}-')
# -{'name': 'John', 'age': 36}
# -John-36-
print(f'{v[name]}')
# NameError: name 'name' is not defined
print(f'{v[age]}')
# NameError: name 'age' is not defined
v = {'person':{'name':'John', 'age':36}}
print(f'-{v}\n-{v['person']}\n-{v['person']['name']}-{v['person']['age']}-')
# -{'person': {'name': 'John', 'age': 36}}
# -{'name': 'John', 'age': 36}
# -John-36-
<variable.key & variable.key()>:
import math
v = math
print(f'{v.pi}')
# 3.141592653589793
print(f'{v.pow}')
# <built-in function pow>
print(f'{v.pow(3, 2)}')
# 9.0
<!s & !r & !a>:
*Memos:
-
!sis str() which can create a string. -
!ris repr() which can create a printable string. -
!ais ascii() which can create the printable string of ASCII characters. *Non-ASCII characters are represented with\x,\u, or\Uescape.
v = "Jφhи\tSмiтh"
print(f"{v!s}")
# Jφhи Sмiтh
print(f"{v!r}")
# 'Jφhи\tSмiтh'
print(f"{v!a}")
# 'J\u03c6h\u0438\tS\u043ci\u0442h'
v = 'I\'m Jφhи\tSмiтh.'
print(f'{v!s}')
# I'm Jφhи Sмiтh.
print(f'{v!r}')
# "I'm Jφhи\tSмiтh."
print(f'{v!a}')
# "I'm J\u03c6h\u0438\tS\u043ci\u0442h."
<{{ & }}>
*Memos:
-
{can escape{. -
}can escape}.
print(f'The bracket {{ is escaped.')
# The bracket { is escaped.
print(f'The bracket }} is escaped.')
# The bracket } is escaped.
print(f'The {{brackets}} are escaped.')
# The {brackets} are escaped.
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