在Python中读取文件时忽略空行的最简单方法

在Python中读取文件时忽略空行的最简单方法

我将堆栈生成器表达式：

with open(filename) as f_in:    lines = (line.rstrip() for line in f_in) # All lines including the blank ones    lines = (line for line in lines if line) # Non-blank lines

现在，

lines

是所有非空白行。这将使您不必在线路上两次打电话。如果需要行列表，则可以执行以下 *** 作：

with open(filename) as f_in:    lines = (line.rstrip() for line in f_in)     lines = list(line for line in lines if line) # Non-blank lines in a list

您也可以采用单行代码（排除

with

语句）来执行此 *** 作，但是它不再高效且更难阅读：

with open(filename) as f_in:    lines = list(line for line in (l.strip() for l in f_in) if line)

更新：

我同意，由于令牌的重复，这很丑陋。您可以根据需要编写一个生成器：

def nonblank_lines(f):    for l in f:        line = l.rstrip()        if line: yield line

然后像这样调用它：

with open(filename) as f_in:    for line in nonblank_lines(f_in):        # Stuff

更新2：

with open(filename) as f_in:    lines = filter(None, (line.rstrip() for line in f_in))

以及在CPython上（具有确定性引用计数）

lines = filter(None, (line.rstrip() for line in open(filename)))

itertools.ifilter

如果需要生成器，请在Python 2中使用；如果需要列表，请在Python 3

list

中使用。