python - 使用Python修改现有文本文件中的参数

我有一个文本文件（example.txt），看起来像这样：

sn = 50
fs=60
bw=10
temperature=20
ch=10

rx_b_phase = 204c7a76
rx_b_gain  = 113
tx_b_phase = 01ff03e1
tx_b_gain  = 105

#sample_gain
sample_gain_hi = 7dc
sample_gain_mid = 7d0
sample_gain_low = 7c9

psl = 44
pin = -1728

#tmpr_reg   temperature,pa_reg,wfp_reg
tmpr_reg = 1,d4,1b
tmpr_reg = 6,d3,1b
tmpr_reg = 12,d2,1b
tmpr_reg = 17,d1,1b

我需要修改/更新以下参数：rx_b_phase，sample_gain_hi，而无需进行其他任何更改。我将如何使用Python做到这一点？
非常感谢，

最佳答案

您可以使用fileinput模块：

import fileinput
for line in fileinput.input('example.txt', inplace = True):
    if line.startswith('rx_b_phase'):
        #if line starts with rx_b_phase then do something here
        print "rx_b_phase = foo"
    elif line.startswith('sample_gain_hi'):
        #if line starts with sample_gain_hi then do something here
        print "sample_gain_hi = bar"
    else:
        print line.strip()