Using f-strings(PEP 498) style literal string interpolation without Python 3.6.
Accessing the globals and locals.
import os import fmt as f g_foo = 'global-foo' g_bar = 'global-bar' g_num = 23 g_ls = [1, 2, 3] def scope(): l_foo = 'local-foo' l_bar = 'local-bar' print( f('{l_foo}, {l_bar}') ) # 'local-foo, local-bar' print( f('{g_foo}, {g_bar!r}') ) # "global-foo, 'global-bar'" scope() print( f('{{ }}') ) # '{ }' print( f('hex: {g_num:#x}') ) # '0x17' print( f('{os.EX_OK}') ) # '0' print( f('{g_ls[0]}, {g_ls[1]}, {g_ls[2]}') ) # '1, 2, 3'
NOTE: Closure will be a little tricky, must pass the outside scope variables as arguments to f, which added a reference to inside the closure in order this can work.
Expression evaluation.
from datetime import datetime import fmt as f class S(object): def __str__(self): return 'hello' def __repr__(self): return 'hi' def __format__(self, fmt): return 'abcdefg'[int(fmt)] print( f('{1234567890:,}') ) # '1,234,567,890' print( f('{1 + 2}') ) # '3' print( f('{str(1 + 2)!r}') ) # "'3'" print( f('{[i for i in range(5)]}') ) # '[0, 1, 2, 3, 4]' ls = range(5) print( f('{{i for i in ls}}') ) # 'set([0, 1, 2, 3, 4])' or '{0, 1, 2, 3, 4}' print( f('{{k:v for k,v in zip(range(3), range(3, 6))}}') ) # '{0: 3, 1: 4, 2: 5}' print( f('{datetime(1994, 11, 6):%Y-%m-%d}') ) # '1994-11-06' print( f('{list(map(lambda x: x+1, range(3)))}') ) # '[1, 2, 3]' print( f('{S()!s}, {S()!r}, {S():1}') ) # 'hello, hi, b'
Also, you can register some namespaces for convenience.
- NOTE:
locals()
maybe cover theglobals()
,globals()
maybe cover the namespaces that you registered.
Install by pip: :
[sudo] pip install fmt -U