Python书籍示例代码(第六章)

《Python语言程序设计基础（第2版）》嵩天著

第六章

●6 - 1
基本统计值计算

# e9.1CalStatistics.py
from math import sqrt


def getNum():  # 获取用户不定长输入
    nums = []
    iNumStr = input("请输入数字(直接输入回车退出): ")
    while iNumStr != "":
        nums.append(eval(iNumStr))
        iNumStr = input("请输入数字(直接输入回车退出): ")
    return nums


def mean(numbers):  # 计算平均值
    s = 0.0
    for num in numbers:
        s = s + num
    return s / len(numbers)


def dev(numbers, mean):  # 计算方差
    sdev = 0.0
    for num in numbers:
        sdev = sdev + (num - mean) ** 2
    return sqrt(sdev / (len(numbers) - 1))


def median(numbers):  # 计算中位数
    sorted(numbers)
    size = len(numbers)
    if size % 2 == 0:
        med = (numbers[size // 2 - 1] + numbers[size // 2]) / 2
    else:
        med = numbers[size // 2]
    return med


n = getNum()  # 主体函数
m = mean(n)
print("平均值:{},方差:{:.2},中位数:{}.".format(m, dev(n, m), median(n)))


●6 - 2
哈姆雷特英文词频统计


# e10.1CalHamlet.py
def getText():
    txt = open("hamlet.txt", "r").read()
    txt = txt.lower()
    for ch in '!"#$%&()*+,-./:;<=>?@[\]^_‘{|}~':
        txt = txt.replace(ch, " ")  # 将文本中特殊字符替换为空格
    return txt


hamletTxt = getText()
words = hamletTxt.split()
counts = {}
for word in words:
    counts[word] = counts.get(word, 0) + 1
items = list(counts.items())
items.sort(key=lambda x: x[1], reverse=True)
for i in range(10):
    word, count = items[i]
    print("{0:<10}{1:>5}".format(word, count))
6 - 3
带排除的哈姆雷特英文词频统计

# e10.2CalHamlet.py
excludes = {"the", "and", "of", "you", "a", "i", "my", "in"}


def getText():
    txt = open("hamlet.txt", "r").read()
    txt = txt.lower()
    for ch in '!"#$%&()*+,-./:;<=>?@[\]^_‘{|}~':
        txt = txt.replace(ch, " ")  # 将文本中特殊字符替换为空格
    return txt


hamletTxt = getText()
words = hamletTxt.split()
counts = {}
for word in words:
    counts[word] = counts.get(word, 0) + 1
for word in excludes:
    del (counts[word])
items = list(counts.items())
items.sort(key=lambda x: x[1], reverse=True)
for i in range(10):
    word, count = items[i]
    print("{0:<10}{1:>5}".format(word, count))
●6 - 4
三国演义中文词频统计

# e10.3CalThreeKingdoms.py
import jieba

excludes = {}  # {"将军","却说","丞相"}
txt = open("三国演义.txt", "r", encoding='utf-8').read()
words = jieba.lcut(txt)
counts = {}
for word in words:
    if len(word) == 1:  # 排除单个字符的分词结果
        continue
    else:
        counts[word] = counts.get(word, 0) + 1
for word in excludes:
    del (counts[word])
items = list(counts.items())
items.sort(key=lambda x: x[1], reverse=True)
for i in range(15):
    word, count = items[i]
    print("{0:<10}{1:>5}".format(word, count))

●6 - 5
三国演义中文人名词频统计

# e10.4CalThreeKingdoms.py
import jieba

excludes = {"将军", "却说", "荆州", "二人", "不可", "不能", "如此"}
txt = open("三国演义.txt", "r", encoding='utf-8').read()
words = jieba.lcut(txt)
counts = {}
for word in words:
    if len(word) == 1:
        continue
    elif word == "诸葛亮" or word == "孔明曰":
        rword = "孔明"
    elif word == "关公" or word == "云长":
        rword = "关羽"
    elif word == "玄德" or word == "玄德曰":
        rword = "刘备"
    elif word == "孟德" or word == "丞相":
        rword = "曹操"
    else:
        rword = word
    counts[rword] = counts.get(rword, 0) + 1
for word in excludes:
    del (counts[word])
items = list(counts.items())
items.sort(key=lambda x: x[1], reverse=True)
for i in range(5):
    word, count = items[i]
    print("{0:<10}{1:>5}".format(word, count))

●6 - 6
Python之禅

import this
●6 - 7
Python之禅源代码

s = """Gur Mra bs Clguba, ol Gvz Crgref
Ornhgvshy vf orggre guna htyl.
Rkcyvpvg vf orggre guna vzcyvpvg.
Fvzcyr vf orggre guna pbzcyrk.
Pbzcyrk vf orggre guna pbzcyvpngrq.
Syng vf orggre guna arfgrq.
Fcnefr vf orggre guna qrafr.
Ernqnovyvgl pbhagf.
Fcrpvny pnfrf nera'g fcrpvny rabhtu gb oernx gur ehyrf.
Nygubhtu cenpgvpnyvgl orngf chevgl.
Reebef fubhyq arire cnff fvyragyl.
Hayrff rkcyvpvgyl fvyraprq.
Va gur snpr bs nzovthvgl, ershfr gur grzcgngvba gb thrff.
Gurer fubhyq or bar-- naq cersrenoyl bayl bar --boivbhf jnl
gb qb vg.
Nygubhtu gung jnl znl abg or boivbhf ng svefg hayrff lbh'er
Qhgpu.
Abj vf orggre guna arire.
Nygubhtu arire vf bsgra orggre guna *evtug* abj.
Vs gur vzcyrzragngvba vf uneq gb rkcynva, vg'f n onq vqrn.
Vs gur vzcyrzragngvba vf rnfl gb rkcynva, vg znl or n tbbq
vqrn.
Anzrfcnprf ner bar ubaxvat terng vqrn -- yrg'f qb zber bs
gubfr!"""
d = {}
for c in (65, 97):
    for i in range(26):
        d[chr(i + c)] = chr((i + 13) % 26 + c)
print("".join([d.get(c, c) for c in s]))