Python 计算文件中字符串的出现次数

我的代码应该统计在.txt文件中显示恐龙骨骼的所有时间，但我的代码指出所有骨骼显示0次

print('Bones found:')
f=open('bones.txt')
bones = {line.replace('\n', ''): 0 for line in f}
for bone in f:
  if bone in bones:
    bones[bone]=bones[bone]+1

for y in bones:
  print(y+':'+str(bones[y]))

bones.txt文件是：

Ankylosaurus
Pachycephalosaurus
Ankylosaurus
Tyrannosaurus Rex
Ankylosaurus
Struthiomimus
Struthiomimus

它说：

Bones found:
Ankylosaurus:0
Pachycephalosaurus:0
Tyrannosaurus Rex:0
Struthiomimus:0

但是应该说：

Bones found:
Ankylosaurus: 3
Pachycephalosaurus: 1
Tyrannosaurus Rex: 1
Struthiomimus: 2

---

您只能使用迭代器（通过使用

open（file.txt）

获得）。以下代码应适用于您的情况。此代码使用了标准python库中包含的用于计算字符串出现次数的

使用计数器

# import the Counter so it can be used
from collections import Counter
# open the text file in read mode, by using this construct, 
# the lock will be released after the with-block to ensure 
# resources are freed correctly
with open("bones.txt") as file:
    # for every line in the file; remove the \n and insert it into the counter
    counts = Counter(line.strip() for line in file)

# print every key in the counter
for dinosaur in counts:
    print("{}: {}".format(dinosaur, counts[dinosaur]))

使用字典

此代码不使用计数器，但操作完全相同

# open the text file in read mode, by using this construct, 
# the lock will be released after the with-block to ensure 
# resources are freed correctly
with open("bones.txt") as file:
    # create a dictionary to store the counts
    counts = dict()
    # iterate over every line in the file
    for line in file:
        # remove the \n from the line
        stripped = line.strip()

        if stripped in counts:
            # key already exists -> increment it
            counts[stripped] += 1
        else:
            # key doesn't exist -> add it
            counts[stripped] = 1

# print every key in the counts dictionary
for dinosaur in counts:
    print("{}: {}".format(dinosaur, counts[dinosaur]))

输出

Pachycephalosaurus: 1
Struthiomimus: 2
Ankylosaurus: 3
Tyrannosaurus Rex: 1

---

我是初学者。这是我的第四周。你已经用完了你的文件迭代器，你不能在文件上循环多次。@MitchelPaulin这很好，在这种情况下，因为他们在一个

dict

上循环。也在文件上重复两次：一次在dict理解中，第二次在

for

@biwwibourdi中我更新了我的答案也包括一个非反驳性的回答