B ™‘[ศใ@s|dZddlmZmZddlmZddlmZefdd„Zdd „Z efd d „Z d d „Z dd„Z dd„Z efdd„Zdd„ZdS)zP Generic Rules for SymPy This file assumes knowledge of Basic and little else. ้)ฺprint_functionฺdivision)ฺsift้)ฺnewcs‡‡fdd„}|S)a” Create a rule to remove identities isid - fn :: x -> Bool --- whether or not this element is an identity >>> from sympy.strategies import rm_id >>> from sympy import Basic >>> remove_zeros = rm_id(lambda x: x==0) >>> remove_zeros(Basic(1, 0, 2)) Basic(1, 2) >>> remove_zeros(Basic(0, 0)) # If only identites then we keep one Basic(0) See Also: unpack cshttˆ|jƒƒ}t|ƒdkr |St|ƒt|ƒkrRˆ|jfdd„t|j|ƒDƒžŽSˆ|j|jdƒSdS)z Remove identities rcSsg|]\}}|s|‘qSฉr)ฺ.0ฺargฺxrr๚2lib/python3.7/site-packages/sympy/strategies/rl.py๚ #sz/rm_id..ident_remove..N)ฺlistฺmapฺargsฺsumฺlenฺ __class__ฺzip)ฺexprZids)ฺisidrrr ฺ ident_removes zrm_id..ident_remover)rrrr)rrr ฺrm_id s rcs‡‡‡fdd„}|S)a Create a rule to conglomerate identical args >>> from sympy.strategies import glom >>> from sympy import Add >>> from sympy.abc import x >>> key = lambda x: x.as_coeff_Mul()[1] >>> count = lambda x: x.as_coeff_Mul()[0] >>> combine = lambda cnt, arg: cnt * arg >>> rl = glom(key, count, combine) >>> rl(Add(x, -x, 3*x, 2, 3, evaluate=False)) 3*x + 5 Wait, how are key, count and combine supposed to work? >>> key(2*x) x >>> count(2*x) 2 >>> combine(2, x) 2*x csht|jˆƒ}t‡fdd„| กDƒƒ}‡fdd„| กDƒ}t|ƒt|jƒkr`tt|ƒf|žŽS|SdS)z2 Conglomerate together identical args x + x -> 2x c3s$|]\}}|ttˆ|ƒƒfVqdS)N)rr)rฺkr)ฺcountrr ๚ Dsz-glom..conglomerate..csg|]\}}ˆ||ƒ‘qSrr)rZmatZcnt)ฺcombinerr r Esz.glom..conglomerate..N)rrฺdictฺitemsฺsetrฺtype)rฺgroupsZcountsZnewargs)rrฺkeyrr ฺ conglomerateAs  zglom..conglomerater)r!rrr"r)rrr!r ฺglom)s r#cs‡‡fdd„}|S)zว Create a rule to sort by a key function >>> from sympy.strategies import sort >>> from sympy import Basic >>> sort_rl = sort(str) >>> sort_rl(Basic(3, 1, 2)) Basic(1, 2, 3) csˆ|jft|jˆdžŽS)N)r!)rฺsortedr)r)r!rrr ฺsort_rlWszsort..sort_rlr)r!rr%r)r!rr ฺsortMs r&cs‡‡fdd„}|S)aW Turns an A containing Bs into a B of As where A, B are container types >>> from sympy.strategies import distribute >>> from sympy import Add, Mul, symbols >>> x, y = symbols('x,y') >>> dist = distribute(Mul, Add) >>> expr = Mul(2, x+y, evaluate=False) >>> expr 2*(x + y) >>> dist(expr) 2*x + 2*y cspxjt|jƒD]\\}}t|ˆƒr |jd|…|j||j|dd…‰}‰ˆ‡‡‡fdd„|jDƒŽSq W|S)Nrcsg|]}ˆˆ|fˆŽ‘qSrr)rr )ฺAฺfirstฺtailrr r osz5distribute..distribute_rl..)ฺ enumeraterฺ isinstance)rฺir ฺb)r'ฺB)r(r)r ฺ distribute_rlks  . z!distribute..distribute_rlr)r'r.r/r)r'r.r ฺ distribute[sr0cs‡‡fdd„}|S)z Replace expressions exactly cs|ˆkr ˆS|SdS)Nr)r)ฺar-rr ฺsubs_rluszsubs..subs_rlr)r1r-r2r)r1r-r ฺsubsssr3cCs t|jƒdkr|jdS|SdS)z Rule to unpack singleton args >>> from sympy.strategies import unpack >>> from sympy import Basic >>> unpack(Basic(2)) 2 rrN)rr)rrrr ฺunpack~s r4cCsL|j}g}x0|jD]&}|j|kr.| |jกq| |กqW||jf|žŽS)z9 Flatten T(a, b, T(c, d), T2(e)) to T(a, b, c, d, T2(e)) )rrฺextendฺappend)rrฺclsrr rrr ฺflatten‹s  r8cCs2yt|ƒttt|jƒƒŽStk r,|SXdS)zล Rebuild a SymPy tree This function recursively calls constructors in the expression tree. This forces canonicalization and removes ugliness introduced by the use of Basic.__new__ N)rr rฺrebuildrฺ Exception)rrrr r9–sr9N)ฺ__doc__Z __future__rrZsympy.utilities.iterablesrฺutilrrr#r&r0r3r4r8r9rrrr ฺs   $