我正在使用以下代码创建成绩分配函数:
def distribution(grades):
available_grades = [ 'A+','A','A-','B+','B','B-','C+','C','C-','F']
fin = open(grades,'r')
gradesList = fin.readline().split(' ')
for c_grade in available_grades:
if c_grade in gradesList:
print('students got '+c_grade)
我使用的grade.txt文件包含所有成绩,我需要一种方法来计算该文本文件中成绩的次数,并打印出这样的数字:
distribution('grades.txt')
6 students got A
2 students got A-
3 students got B+
2 students got B
2 students got B-
4 students got C
1 student got C-
2 students got F
但目前只打印这个:
students got A
students got A-
students got B+
students got B
students got B-
students got C
students got C-
students got F
我的grades.txt文件包含:
A A- C F C C B- B A A A- B B+ B+ B+ C C- B- A A A F
答案 0 :(得分:2)
def distribution(grades):
available_grades = ['A+','A','A-','B+','B','B-','C+','C','C-','F']
with open(grades, 'r') as fin:
gradeCounts = collections.Counter(fin.readline().split())
for grade in available_grades:
print(gradeCounts[grade], 'students got', grade)
答案 1 :(得分:1)
如果您不想使用集合,则以下内容应该有效:
def distribution(grades):
available_grades = [ 'A+','A','A-','B+','B','B-','C+','C','C-','F']
grade_dict = {}
for grade in available_grades:
grade_dict[grade] = 0
fin = open(grades,'r')
gradesList = fin.readline().split()
fin.close()
for grade in gradesList:
grade_dict[grade] += 1
for grade in available_grades:
print(str(grade_dict[grade]) + ' students got ' + grade)
请注意,我已将参数移至split()
,因此它将删除所有空格而不仅仅是空格。
答案 2 :(得分:0)
你可以使用python Counter类。
from collections import counter
# creates a new Counter object
c = Counter()
# your file contents
lst_grades = "A A- C F C C B- B A A A- B B+ B+ B+ C C- B- A A A F"
# turn lst_grades to a list containing the grades
lst_grades = lst_grades.split(" ")
# printing lst_grades for a better idea what lst_grades looks like now
# lst_grades
# > ['A', 'A-', 'C', 'F', 'C', 'C', 'B-', 'B', 'A', 'A', 'A-', 'B', 'B+',
# 'B+', 'B+', 'C', 'C-', 'B-', 'A', 'A', 'A', 'F']
# call the update method of the counter c
# update takes an iterable (e.g. a list)
# and counts the values inside this iterable
c.update(lst_grades)
# now our counter contains a dictionary with the counted grads
# c
# > Counter({'A': 6, 'C': 4, 'B+': 3, 'B': 2, 'F': 2,
# 'B-': 2, 'A-': 2, 'C-': 1})
# you can simply access every counted entry
# c["A"]
# > 6
答案 3 :(得分:0)
或者,熊猫解决方案:
fin = open(grades,'r')
grades_given = fin.readline().split()
fin.close()
pd.Series(grades_given).value_counts().reset_index(name='cnt').\
apply(lambda x: "{cnt} students got {grade}".format(cnt=x['cnt'],
grade=x['index']),axis=1)
0 6 students got A
1 4 students got C
2 3 students got B+
3 2 students got A-
4 2 students got B-
5 2 students got F
6 2 students got B
7 1 students got C-