#sscanf challenge #by baptiste prunier #input format : 2 lines, s and p such as described bellow """ *DAILY CHALLENGE* : Write a sscanf like function. The function gets a string s and a string p (pattern) and returns an array of variables. The pattern can contain: - %d for integer AND double - %s for string - %c for character - any normal asci-char example 1: p = "%c'am %d" s = "I'am 25" result = sscanf(s,p) = ['I',25] example 2: p = "good %s!" s = "good night!" result = sscanf(s,p) = ["night"] info: - If s doesn't match p -> return an empty array - If you can't return arrays with different types store the values as strings and return a string array! EXAMPLE 3: s = "nice 2 meet you!" p = "nice %d %s%c" result = sscanf(s,p) = [2, "meet you", '!'] EXAMPLE 4: s = "ok" p = "%d" res = sscanf(s,p) = [ ] AND PLEASE DO NOT USE ANY BUILT-IN FUNCTION LIKE FORMAT(etc)!!! """ #update : adding a * between the % and the character (s,d or c) means that it needs to be ignored in the result but still be there in the string def is_digit(n): return n >= '0' and n <= '9' def set_is_sep(c): return lambda n : n == c def read_num(s,p,res): si = 0 count = 0 while si < len(s) and (is_digit(s[si]) or s[si] == '.') and count < 2: if s[si] == '.': count += 1 si += 1 if si == len(s): pi = 0 while pi < len(p) - 1 and p[pi] == "%" and (p[pi + 1] == 'c' or (pi < len(p) - 2 and p[pi + 1:pi + 3] == '*c')): if s[si] == '.': count -= 1 si -= 1 pi += 2 if p[pi + 1] == 'c' else 3 res.append(float(s[:si]) if count else int(s[:si])) return si,0 def read_str(s,p,res): i = 0 nc = 0 while i < len(p) - 1 and p[i] == "%" and (p[i + 1] == "c" or (i < len(p) - 2 and p[i + 1] == '*' and p[i + 2] == 'c')): i += 2 if p[i + 1] == 'c' else 3 nc += 1 if i < len(p) - 1 and p[i] == "%": if p[i + 1] == "s" or (i < len(p) - 2 and p[i + 1] == "*" and p[i + 2] == "s"): return None else: sep = is_digit elif i < len(p): sep = set_is_sep(p[i]) elif i: res.append(s[:-nc]) for j in range(-nc,0): res.append(s[j]) return len(s),i else: res.append(s[:]) return len(s),i si = 0 while not sep(s[si]): si += 1 res.append(s[:si - nc]) tmp = i - 2 for j in range(-nc,0): if p[tmp] == '%': res.append(s[si - j]) tmp -= 2 else: tmp -= 3 return si,i def sscanf(s : str, p : str): try: si = 0 pi = 0 res = [] while pi < len(p) - 1: if p[pi] == "%" and (p[pi + 1] in "sdc" or (pi < len(p) - 2 and p[pi + 1] == '*' and p[pi + 2] in "sdc")): if p[pi + 1] == "c" or (pi < len(p) - 2 and p[pi + 1] == "*" and p[pi + 2] == "c"): if p[pi + 1] == "c": res.append(s[si]) pi += 2 else: pi += 3 si += 1 elif p[pi + 1] == "d" or (pi < len(p) - 2 and p[pi + 1] == "*" and p[pi + 2] == "d"): if p[pi + 1] == "d": d = read_num(s[si:],p[pi + 2:], res) else: d = read_num(s[si:],p[pi + 3:],[]) pi += 1 assert d != None pi += d[1] + 2 si += d[0] else: if p[pi + 1] == "s": d = read_str(s[si:],p[pi + 2:], res) else: i = len(res) d = read_str(s[si:],p[pi + 3:], res) if d: res.pop(i) pi += 1 assert d != None pi += d[1] + 2 si += d[0] else: assert p[pi] == s[si] pi += 1 si += 1 if pi < len(p): assert p[pi] == s[si] return res except: return [] print("--- OFFICIAL TESTS ---") p = "%c'am %d" s = "I'am 25" result = sscanf(s,p) print("sscanf(\"",s,"\",\"",p,"\") = ",result,sep="") print() p = "good %s!" s = "good night!" result = sscanf(s,p) print("sscanf(\"",s,"\",\"",p,"\") = ",result,sep="") print() s = "nice 2 meet you!" p = "nice %d %s%c" result = sscanf(s,p) print("sscanf(\"",s,"\",\"",p,"\") = ",result,sep="") print() s = "ok" p = "%d" result = sscanf(s,p) print("sscanf(\"",s,"\",\"",p,"\") = ",result,sep="") print() s = "nice 2 meet you !" p = "nice %d %*s%c" result = sscanf(s,p) print("sscanf(\"",s,"\",\"",p,"\") = ",result,sep="") print() print("--- YOUR TEST ---") s=input() try: p=input() except: print("You have to input 2 lines") else: result = sscanf(s,p) print("sscanf(\"",s,"\",\"",p,"\") = ",result,sep="") print()