00foo.py

from prestring.python import Module

m = Module()
with m.def_("foo"):
    m.return_("'foo'")
print(m)

01foo.py

from prestring.python import Module


def emit_foo(m: Module, name: str, *, sep: str):
    with m.def_(name, "message: str"):
        m.return_(f"f'foo{sep}{{message}}'")
    return m


m = Module()
m = emit_foo(m, "do_foo", sep=":")

with m.for_("i", "range(5)"):
    m.stmt("do_foo(str(i))")

print(m)

02varname.py

from prestring.python import Module

m = Module()
m.import_("math")
m.sep()

with m.def_('rmse', 'xs', 'ys'):
    m.stmt('acc = 0')
    m.stmt('assert len(xs) == len(ys)')
    with m.for_('x, y', 'zip(xs, ys)'):
        m.stmt('acc += (x - y) ** 2')
    m.return_('math.sqrt(acc / len(xs))')

# m.stmt('xs = [92, 95, 110, 114, 100, 98, 93]')
# m.stmt('ys = [95, 93, 100, 114, 105, 100, 96]')
print(m)

03use-import.py

from prestring.python import Module

m = Module()

m.import_("re")
m.import_("sys")
m.sep()
m.stmt(
    "pattern = re.compile({!r}, re.IGNORECASE)",
    r"^(?P<label>DEBUG|INFO|WARNING|ERROR|CRITICAL):\s*(?P<message>\S+)",
)

with m.for_("line", "sys.stdin"):
    m.stmt("m = pattern.search(line)")
    with m.if_("m is not None"):
        m.stmt("print(m.groupdict())")
print(m)

04use-import-symbol.py

from prestring.python import Module

m = Module()

re = m.import_("re")
sys = m.import_("sys")

m.sep()
m.stmt(
    "pattern = {}",
    re.compile(
        r"^(?P<label>DEBUG|INFO|WARNING|ERROR|CRITICAL):\s*(?P<message>\S+)",
        re.IGNORECASE,
    ),
)

with m.for_("line", sys.stdin):
    m.stmt("m = pattern.search(line)")
    with m.if_("m is not None"):
        m.stmt("print(m.groupdict())")
print(m)

05-0304.diff

--- 03use-import.py	2020-02-23 13:37:24.000000000 +0900
+++ 04use-import-symbol.py	2020-02-23 13:36:11.000000000 +0900
@@ -2,15 +2,19 @@
 
 m = Module()
 
-m.import_("re")
-m.import_("sys")
+re = m.import_("re")
+sys = m.import_("sys")
+
 m.sep()
 m.stmt(
-    "pattern = re.compile({!r}, re.IGNORECASE)",
-    r"^(?P<label>DEBUG|INFO|WARNING|ERROR|CRITICAL):\s*(?P<message>\S+)",
+    "pattern = {}",
+    re.compile(
+        r"^(?P<label>DEBUG|INFO|WARNING|ERROR|CRITICAL):\s*(?P<message>\S+)",
+        re.IGNORECASE,
+    ),
 )
 
-with m.for_("line", "sys.stdin"):
+with m.for_("line", sys.stdin):
     m.stmt("m = pattern.search(line)")
     with m.if_("m is not None"):
         m.stmt("print(m.groupdict())")

06use-import-code-object.py

from prestring.python import Module
from prestring.codeobject import CodeObjectModule

m = Module()
co = CodeObjectModule(m)

re = co.import_("re")
sys = co.import_("sys")

m.sep()
pattern = co.let(
    "pattern",
    re.compile(
        r"^(?P<label>DEBUG|INFO|WARNING|ERROR|CRITICAL):\s*(?P<message>\S+)",
        re.IGNORECASE,
    ),
)


with m.for_("line", sys.stdin):
    matched = co.let("matched", pattern.search(co.symbol("line")))
    with m.if_(f"{matched} is not None"):
        print_ = co.symbol("print")
        m.stmt(print_(matched.groupdict()))
print(m)

07-0406.diff

--- 04use-import-symbol.py	2020-02-23 13:36:11.000000000 +0900
+++ 06use-import-code-object.py	2020-02-23 13:49:22.000000000 +0900
@@ -1,21 +1,25 @@
 from prestring.python import Module
+from prestring.codeobject import CodeObjectModule
 
 m = Module()
+co = CodeObjectModule(m)
 
-re = m.import_("re")
-sys = m.import_("sys")
+re = co.import_("re")
+sys = co.import_("sys")
 
 m.sep()
-m.stmt(
-    "pattern = {}",
+pattern = co.let(
+    "pattern",
     re.compile(
         r"^(?P<label>DEBUG|INFO|WARNING|ERROR|CRITICAL):\s*(?P<message>\S+)",
         re.IGNORECASE,
     ),
 )
 
+
 with m.for_("line", sys.stdin):
-    m.stmt("m = pattern.search(line)")
-    with m.if_("m is not None"):
-        m.stmt("print(m.groupdict())")
+    matched = co.let("matched", pattern.search(co.symbol("line")))
+    with m.if_(f"{matched} is not None"):
+        print_ = co.symbol("print")
+        m.stmt(print_(matched.groupdict()))
 print(m)

Makefile

00:
	python $(shell echo $@*.py)
01:
	python $(shell echo $@*.py)
02:
	python $(shell echo $@*.py)
03:
	python $(shell echo $@*.py)
04:
	python $(shell echo $@*.py)
05:
	diff -u 03*.py 04*.py > 05-0304.diff
06:
	python $(shell echo $@*.py)
07:
	diff -u 04*.py 06*.py > 07-0406.diff