在字典列表中的列表中搜索字符串

Question

我正在尝试确定搜索字典键值的最佳方法。

我似乎找不到能够允许我在列表列表中搜索特定字符串的函数。 我正在尝试让该程序显示采用某种班级类型的学期。

即输入“ ENGR”并返回它显示在“ fall14”，“ fall15”和“ spring16”中。

有人可以为我指出从列表中的列表中提取数据的正确方向吗？ 我认为我可能需要重新构造定义键的方式。

Classes = dict()
Classes["FALL14"] = ("ENGR","156","01",'Engineering 3'),("ENGR","156","01",'Engineering 4'),("SCI","156","01",'Chemistry 1'),("ENGL","156","01",'Writing 1')
Classes['SPRING15'] =("ENGL","156","01",'Writing 2'),("MATH","156","01",'Calculus 1'),("MATH","156","01",'Calculus 2'),("MATH","156","01",'Calculus 3')
Classes['FALL15'] =("MATH","156","01",'Differential Equations'),("ENGR","156","01",'Solid Works'),("ENGR","156","01",'MATLAB'),("ENGR","156","01",'Dynamics')
Classes['SPRING16'] = ("ENGR","156","01",'Statics'),("ART","156","01",'Drawing 1'),("ENGR","156","01",'Fluid Dynamics'),("ENGR","156","01",'Thermodynamics 1')


for semester, information in Classes.items():   #Prints semesters that a class type was taken.
    if information ==  "ENGR":
        print(semester)

Answer 1

假设您要比较的字符串将始终位于嵌套元组的第0个索引处，则可以使用any()匹配内容，例如：

my_str = "ENGR"

#                             v  as per PEP naming convention, it should 
#                             v  start with lower-case
for semester, informations in Classes.items():
    if any(item[0]==my_str for item in informations):
        #       ^  check element at 0th index of each sub-tuple 
        #          for the match with `my_str`
        print(semester)  # OR, print(semester.lower()) to print the lower cased
                         # string as mentioned in desired result

它将打印：

FALL14
FALL15
SPRING16

Answer 2

您需要再往下走。 您的循环为您提供了一组集合。 然后，您需要遍历这些集合

Classes = dict()
Classes["FALL14"] = ("ENGR","156","01",'Engineering 3'),("ENGR","156","01",'Engineering 4'),("SCI","156","01",'Chemistry 1'),("ENGL","156","01",'Writing 1')
Classes['SPRING15'] =("ENGL","156","01",'Writing 2'),("MATH","156","01",'Calculus 1'),("MATH","156","01",'Calculus 2'),("MATH","156","01",'Calculus 3')
Classes['FALL15'] =("MATH","156","01",'Differential Equations'),("ENGR","156","01",'Solid Works'),("ENGR","156","01",'MATLAB'),("ENGR","156","01",'Dynamics')
Classes['SPRING16'] = ("ENGR","156","01",'Statics'),("ART","156","01",'Drawing 1'),("ENGR","156","01",'Fluid Dynamics'),("ENGR","156","01",'Thermodynamics 1')

for semester, information in Classes.items():   
    for classes in information:
         if 'ENGR' in classes:
                 print classes

Answer 3

试试看。 您需要继续深入数据结构。

Classes = dict()
Classes["FALL14"] = ("ENGR","156","01",'Engineering 3'),("ENGR","156","01",'Engineering 4'),("SCI","156","01",'Chemistry 1'),("ENGL","156","01",'Writing 1')
Classes['SPRING15'] =("ENGL","156","01",'Writing 2'),("MATH","156","01",'Calculus 1'),("MATH","156","01",'Calculus 2'),("MATH","156","01",'Calculus 3')
Classes['FALL15'] =("MATH","156","01",'Differential Equations'),("ENGR","156","01",'Solid Works'),("ENGR","156","01",'MATLAB'),("ENGR","156","01",'Dynamics')
Classes['SPRING16'] = ("ENGR","156","01",'Statics'),("ART","156","01",'Drawing 1'),("ENGR","156","01",'Fluid Dynamics'),("ENGR","156","01",'Thermodynamics 1')


for semester, information in Classes.items():   #Prints semesters that a class type was taken.    
    for course_info in Classes[semester]:
        if course_info[0] ==  "ENGR":
            print(semester)