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python中的ln函数

math.exp() - 自然指数函数 e^x math.sin() - 正弦函数 sin(x) math.cos() - 余弦函数 cos(x) math.e - 数学自然数 = 2.71828....

python命令通常存在/usr/bin/python和/usr/local/bin/python下面,一般是符号链接,优先使用后者,如果有2.6和2.7两个版本,并且/usr/bin/python --> /usr/bin/python2.6/usr/local/bin/python --> /usr/local/bin/python2.7此时系统默认使用2.7...

def itercolumn(lines, column_line): block = [] for ln in lines: block.append(ln) if len(block) == column_line: yield block block = [] if 0 < len(block) < column_line: block = block + [''] * (column_line - len(block)) yield bloc...

欧拉常数(Euler-Mascheroni constant) 学过高等数学的人都知道,调和级数S=1+1/2+1/3+……是发散的,证明如下: 由于ln(1+1/n)ln(1+1)+ln(1+1/2)+ln(1+1/3)+…+ln(1+1/n) =ln2+ln(3/2)+ln(4/3)+…+ln[(n+1)/n] =ln[2*3/2*4/3*…*(n+1)/n]=ln(n+1) 由于 ...

import repatt = re.compile("\w+")def makeIndex(filename): index = {} with open(filename) as handle: for i, ln in enumerate(handle): for word in patt.findall(ln): index.setdefault(word, []).append(i+1) return indexdef printIndex...

代码基于python 2.6。功能已写成函数,用的简单语法,很好懂。 新文件文件名自动附加"_back"。不懂再问。 import os, time def readKeys(fileName): keys = [] f = open(fileName, "r") while True: line = f.readline() if not line: break key...

[root@test tmp]# mkdir d1 d2 [root@test tmp]# ls d1 d2 [root@test tmp]# ln d1 d2 /dev/null ln: target `/dev/null' is not a directory

创建符号链接的方法是: ln -s 源文件/目录名 符号链接名,例如: ln -s /usr/bin/python3.3 /usr/bin/python ln -s /etc/apache2/sites-...

简单来说,比如这样: def clear_line(ln): if not ln.startsWith('W:'): return None if ln=='W:': return None # parse this line # replace char ln = ln.replace('"', '') # other replace # ... return lnfilename = 'xxx.txt'lines = open...

建立新的链接 sudo ln -s /System/Library/Frameworks/Python.framework/Versions/3.3/bin/pydoc3.3 /usr/bin/pydoc sudo ln -s /System/Library/Frameworks/Python.framework/Versions/3.3/bin/python3.3 /usr/bin/python sudo ln -s /System/L...

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