B e‹d+ใ@sldZddlmZddlmZefdd„Zdd„Zefd d „Zd d „Zd d„Z dd„Z efdd„Z dd„Z dS)zP Generic Rules for SymPy This file assumes knowledge of Basic and little else. ้)ฺsift้)ฺnewcs‡‡fdd„}|S)aร Create a rule to remove identities. isid - fn :: x -> Bool --- whether or not this element is an identity. Examples ======== >>> from sympy.strategies import rm_id >>> from sympy import Basic, S >>> remove_zeros = rm_id(lambda x: x==0) >>> remove_zeros(Basic(S(1), S(0), S(2))) Basic(1, 2) >>> remove_zeros(Basic(S(0), S(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๚`/work/yifan.wang/ringdown/master-ringdown-env/lib/python3.7/site-packages/sympy/strategies/rl.py๚ $sz/rm_id..ident_remove..N)ฺlistฺmapฺargsฺsumฺlenฺ __class__ฺzip)ฺexprZids)ฺisidrrr ฺ ident_removes zrm_id..ident_remover)rrrr)rrr ฺrm_id s rcs‡‡‡fdd„}|S)a6 Create a rule to conglomerate identical args. Examples ======== >>> from sympy.strategies import glom >>> from sympy import Add >>> from sympy.abc import x >>> key = lambda x: x.as_coeff_Mul()[1] >>> count = lambda x: x.as_coeff_Mul()[0] >>> combine = lambda cnt, arg: cnt * arg >>> rl = glom(key, count, combine) >>> rl(Add(x, -x, 3*x, 2, 3, evaluate=False)) 3*x + 5 Wait, how are key, count and combine supposed to work? >>> key(2*x) x >>> count(2*x) 2 >>> combine(2, x) 2*x csdt|jˆƒ}‡fdd„| กDƒ}‡fdd„| กDƒ}t|ƒt|jƒkr\tt|ƒf|žŽS|SdS)z2 Conglomerate together identical args x + x -> 2x cs i|]\}}ttˆ|ƒƒ|“qSr)rr )rฺkr )ฺcountrr ๚ Hsz.glom..conglomerate..csg|]\}}ˆ||ƒ‘qSrr)rฺmatZcnt)ฺcombinerr r Isz.glom..conglomerate..N)rr ฺitemsฺsetrฺtype)rฺgroupsฺcountsZnewargs)rrฺkeyrr ฺ conglomerateEs  zglom..conglomerater)r rrr!r)rrr r ฺglom*s r"cs‡‡fdd„}|S)z๏ Create a rule to sort by a key function. Examples ======== >>> from sympy.strategies import sort >>> from sympy import Basic, S >>> sort_rl = sort(str) >>> sort_rl(Basic(S(3), S(1), S(2))) Basic(1, 2, 3) csˆ|jft|jˆdžŽS)N)r )rฺsortedr )r)r rrr ฺsort_rl^szsort..sort_rlr)r rr$r)r rr ฺsortQs 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 vsz5distribute..distribute_rl..)ฺ enumerater ฺ isinstance)rฺirฺb)r&ฺB)r'r(r ฺ distribute_rlrs  . z!distribute..distribute_rlr)r&r-r.r)r&r-r ฺ distributebsr/cs‡‡fdd„}|S)z Replace expressions exactly cs|ˆkr ˆS|SdS)Nr)r)ฺar,rr ฺsubs_rl|szsubs..subs_rlr)r0r,r1r)r0r,r ฺsubszsr2cCs t|jƒdkr|jdS|SdS)z• Rule to unpack singleton args >>> from sympy.strategies import unpack >>> from sympy import Basic, S >>> unpack(Basic(S(2))) 2 rrN)rr )rrrr ฺunpack…s r3cCsL|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)) )rr ฺextendฺappend)rrฺclsr rrrr ฺflatten’s  r7cCs$|jr |S|jttt|jƒƒŽSdS)z็ Rebuild a SymPy tree. Explanation =========== This function recursively calls constructors in the expression tree. This forces canonicalization and removes ugliness introduced by the use of Basic.__new__ N)Zis_Atomฺfuncr r ฺrebuildr )rrrr r9s r9N) ฺ__doc__Zsympy.utilities.iterablesrฺutilrrr"r%r/r2r3r7r9rrrr ฺs   '