将文本列表格式化为列

Question

我想把一串字符串输出成两列的格式。通常把字符串列表变成“正常文本”的方法是用string.join这个方法。不过，它只能接收两个参数，所以我只能用"\n"来做成一列。我试着用一个循环在列之间加个制表符，但逻辑没有正确运行。

我找到一个ActiveState页面，上面有一种比较复杂的方法，但那是四年前的事了。现在有没有更简单的方法呢？

---

编辑 这是我想用的列表。

skills_defs = ["ACM:Aircraft Mechanic", "BC:Body Combat", "BIO:Biology",
    "CBE:Combat Engineer", "CHM:Chemistry", "CMP:Computers", 
    "CRM:Combat Rifeman", "CVE:Civil Engineer", "DIS:Disguise",
    "ELC:Electronics","EQ:Equestrian", "FO:Forward Observer",
    "FOR:Forage", "FRG:Forgery", "FRM:Farming", "FSH:Fishing",
    "GEO:Geology", "GS:Gunsmith", "HW:Heavy Weapons", "IF:Indirect Fire",
    "INS:Instruction", "INT:Interrogation", "JP:Jet Pilot", "LB:Longbow",
    "LAP:Light Aircraft Pilot", "LCG:Large Caliber Gun", "LNG:Language",
    "LP:Lockpick", "MC:Melee Combat", "MCY:Motorcycle", "MEC:Mechanic",
    "MED:Medical", "MET:Meterology", "MNE:Mining Engineer",
    "MTL:Metallurgy", "MTN:Mountaineering", "NWH:Nuclear Warhead",
    "PAR:Parachute", "PST:Pistol", "RCN:Recon", "RWP:Rotary Wing Pilot",
    "SBH:Small Boat Handling","SCD:Scuba Diving", "SCR:Scrounging",
    "SWM:Swimming", "TW:Thrown Weapon", "TVD:Tracked Vehicle Driver",
    "WVD:Wheeled Vehicle Driver"]

我只是想把这个列表输出成简单的两列格式，以节省空间。理想情况下，列之间应该有标准的间距，但我可以适应。

ACM:Aircraft Mechanic        BC:Body Combat 
BIO:Biology         CBE:Combat Engineer 
CHM:Chemistry       CMP:Computers
CRM:Combat Rifeman      CVE:Civil Engineer 
DIS:Disguise            ELC:Electronics 
EQ:Equestrian           FO:Forward Observer
FOR:Forage          FRG:Forgery 
FRM:Farming             FSH:Fishing
GEO:Geology             GS:Gunsmith 
HW:Heavy Weapons        IF:Indirect Fire
INS:Instruction             INT:Interrogation 
JP:Jet Pilot            LB:Longbow
 LAP:Light Aircraft Pilot       LCG:Large Caliber Gun 
LNG:Language            LP:Lockpick 
MC:Melee Combat         MCY:Motorcycle 
MEC:Mechanic            MED:Medical 
MET:Meterology      MNE:Mining Engineer
MTL:Metallurgy      MTN:Mountaineering 
NWH:Nuclear Warhead     PAR:Parachute 
PST:Pistol          RCN:Recon 
RWP:Rotary Wing Pilot       SBH:Small Boat Handling 
SCD:Scuba Diving        SCR:Scrounging
SWM:Swimming        TW:Thrown Weapon 
TVD:Tracked Vehicle Driver  WVD:Wheeled Vehicle Driver

Answer 1

这段话有点啰嗦，所以我把它分成了两部分。

def columns( skills_defs, cols=2 ):
    pairs = [ "\t".join(skills_defs[i:i+cols]) for i in range(0,len(skills_defs),cols) ]
    return "\n".join( pairs )

显然，这也可以写成一个很长很长的语句。

对于奇数个技能，这种写法也是有效的。

Answer 2

这个可以用

it = iter(skills_defs)
for i in it:
    print('{:<60}{}'.format(i, next(it, "")))

你可以看看这里： 字符串格式化的例子

Answer 3

有两列数据，用制表符分开，然后把它们合成一行。可以看看 itertools 这个库，里面有一些迭代器的工具，可以帮你实现更节省空间的解决方案。

import string
def fmtpairs(mylist):
    pairs = zip(mylist[::2],mylist[1::2])
    return '\n'.join('\t'.join(i) for i in pairs)

print fmtpairs(list(string.ascii_uppercase))

A   B
C   D
E   F
G   H
I   J
...

哎呀...被 S.Lott 抓住了（谢谢你）。

这是一个更通用的解决方案，可以处理任意数量的列和奇怪的列表。这个方法稍微修改了一下来自 S.lott 的内容，使用生成器来节省空间。

def fmtcols(mylist, cols):
    lines = ("\t".join(mylist[i:i+cols]) for i in xrange(0,len(mylist),cols))
    return '\n'.join(lines)