Question

我有一个txt文件，其中包含以下条目：

Rx = 34                  // Counter gets incremented = 1, since the Rx was found for the first time 
Rx = 2
Rx = 10
Tx = 2
Tx = 1
Rx = 3                   // Counter gets incremented = 2, since the Rx was found for the first time after Tx
Rx = 41
Rx = 3
Rx = 19

我只想增加第一次重复的“ Rx”的计数，而不是文本文件中所有Rx的计数。我的代码如下：

import re

f = open("test.txt","r")
count = 0

for lines in f:
    m = re.search("Rx = \d{1,2}", lines)
    if m:
        count +=1

print count

但这给了我txt文件中所有Rx的计数。我希望输出为2而不是7。

请帮帮我！

Answer 1

打破循环，因为您只需要查找重复。

import re

f = open("test.txt","r")
count = 0

for lines in f:
    m = re.search("Rx = \d{1,2}", lines)
    if m:
        count +=1
    if count >=2:
        break
print count

Answer 2

说if m:，只要m != 0，计数就会继续增加。如果只想获得前2个，则需要引入一些其他逻辑。

Answer 3

import re

f = open("test.txt","r")
count = 0

for lines in f:
    m = re.search("Rx = \d{1,2}", lines)
    if m:
        count +=1
    if count >=2:
        break

print(m.group(0))

Answer 4

如果要查找重复1x的Rx的计数：

import re
rx_count = {}
with open("test.txt","r") as f:
    count = 0
    for lines in f:
        if line.startswith('Rx'): rx_count[lines] = rx_count.get(lines,0)+1

现在您在rx_count中有一个计数器字典，我们过滤掉所有大于1的值，然后将这些值相加，然后打印出计数

rx_count = {k:v for k,v in rx_count.interitems() if v > 1}
count = sum(rx_count.values())

print count

Answer 5

要完全按照自己的意愿进行操作，您需要跟踪已经看到的字符串。

您可以通过使用一组来跟踪您看到的内容直到重复，然后仅计算该字符串的出现次数来做到这一点。

这个例子可以做到

import re

count = 0
matches = set()

with open("test.txt", "r") as f:
    for line in f:
        m = re.search(r"Rx = \d{1,2}", line)
        if not m:
            # Skip the rest if no match
            continue

        if m.group(0) not in matches:
            matches.add(m.group(0))
        else:
            # First string we saw
            first = m.group(0)
            count = 2
            break

    for line in f:
        m = re.search(r"Rx = \d{1,2}", line)
        ## This or whatever check you want to do
        if m.group(0) == first:
            count += 1

print(count)

Python：如何在变量重复时增加计数

5 个答案: