
[4**3,2+3.4**2,(1+1j)**2]


a = "... but a giant leap for mankind."
num=a.index('leap')
print(a[0:num]+a[num+4:])


s = "CAGTACCAAGTGAAAGAT"
s.count('A')


a=[1,2,3]
b=[4,5,6]
c=a+b

# or

d=a
d.extend(b)
print (c,d)


x=3.7
(x>3.4 and x<=6.6) or (x==2)


dict={'snake':'Schlange','jungle':'Dschungel','lives':'lebt','in':'in','the':'der'}

s="The snake lives in the jungle"
for word in s.split():
    print (dict[word.lower()])


for i in range(2,1000):
    is_prime=True
    for j in range(2,i):
        if (i%j==0):
            is_prime=False
    if is_prime:
        print (i)


for i in range(2,1000):
    is_prime=True
    for j in range(2,i):
        if (i%j==0):
            is_prime=False
            break
    if is_prime:
        print (i)


# very terse:
a, b = 0, 1
while a < 100000:
    print(a)
    a, b = b, a + b


#Fibonacci sequence with index
#
l=[0]
i=0
x=1

while x<100000:
    l.append(x)     # add x_i
    x=l[i]+l[i+1]   # work out x_i+1
    i=i+1
    
print (len(l))


# determine square Fibonaccis
l=[0]
x=1

while x<100000:
    l.append(x)
    x=l[-2]+l[-1]

# print square Fibonacci numbers
for fibonacci in l:
    is_square=False
    for j in range(fibonacci):
        if j*j==fibonacci:
            is_square=True
            break
    if is_square:
        print ("square number =",fibonacci)

square number = 144


s='pbatenghyngvbaf lbh unir fhpprrqrq va qrpelcgvat gur fgevat'

base=ord('a') # ascii code for 'a'
decode=-13
res=''
for character in s.lower():
    if character==' ':
        t=character
    else:
        ascii=ord(character)
        t=chr(((ascii+decode)-base)%26+base) # (ascii-97)%26 in range 0 ... 25
    res+=t
print (decode,res)


s='pbatenghyngvbaf lbh unir fhpprrqrq va qrpelcgvat gur fgevat'

base=ord('a') # ascii code for 'a'
decode=-13

res=''
for character in s.lower():
    if character==' ':
        tt=ord(' ')
    else:
        ascii=ord(character)
        tt=ascii+decode
        if tt>=base+26:
            tt-=26
        elif tt<base:
            tt+=26
    res+=chr(tt)
print (decode,res)


def caesar_encrypt(message,shift):
    base=ord('a')
    res=''
    for character in message.lower():
        if character==' ':
            tt=ord(' ')
        else:
            ascii=ord(character)
            tt=ascii+shift
            if tt>=base+26:
                tt-=26
            elif tt<base:
                tt+=26
        res+=chr(tt)
    return res

caesar_encrypt(s,-13)

'congratulations you have succeeded in decrypting the string'


s='wxkxmh ngynlcb cqn byjwrbq rwzdrbrcrxw'


for shift in range(-10,20):
    print (shift,caesar_encrypt(s,shift))

-10 mnancx dwodbsr sgd rozmhrg hmpthrhshnm
-9 nobody expects the spanish inquisition
-8 opcpez fyqfdut uif tqbojti jorvjtjujpo
-7 pqdqfa gzrgevu vjg urcpkuj kpswkukvkqp
-6 qrergb hashfwv wkh vsdqlvk lqtxlvlwlrq
-5 rsfshc ibtigxw xli wtermwl mruymwmxmsr
-4 stgtid jcujhyx ymj xufsnxm nsvznxnynts
-3 tuhuje kdvkizy znk yvgtoyn otwaoyozout
-2 uvivkf lewljaz aol zwhupzo puxbpzpapvu
-1 vwjwlg mfxmkba bpm axivqap qvycqaqbqwv
0 wxkxmh ngynlcb cqn byjwrbq rwzdrbrcrxw
1 xylyni ohzomdc dro czkxscr sxaescsdsyx
2 yzmzoj piapned esp dalytds tybftdtetzy
3 zanapk qjbqofe ftq ebmzuet uzcgueufuaz
4 abobql rkcrpgf gur fcnavfu vadhvfvgvba
5 bcpcrm sldsqhg hvs gdobwgv wbeiwgwhwcb
6 cdqdsn tmetrih iwt hepcxhw xcfjxhxixdc
7 dereto unfusji jxu ifqdyix ydgkyiyjyed
8 efsfup vogvtkj kyv jgrezjy zehlzjzkzfe
9 fgtgvq wphwulk lzw khsfakz afimakalagf
10 ghuhwr xqixvml max litgbla bgjnblbmbhg
11 hivixs yrjywnm nby mjuhcmb chkocmcncih
12 ijwjyt zskzxon ocz nkvidnc dilpdndodji
13 jkxkzu atlaypo pda olwjeod ejmqeoepekj
14 klylav bumbzqp qeb pmxkfpe fknrfpfqflk
15 lmzmbw cvncarq rfc qnylgqf glosgqgrgml
16 mnancx dwodbsr sgd rozmhrg hmpthrhshnm
17 nobody expects the spanish inquisition
18 opcpez fyqfdut uif tqbojti jorvjtjujpo
19 pqdqfa gzrgevu vjg urcpkuj kpswkukvkqp

Python course University of Heidelberg Summer 2025¶

Solutions Day 1 (April 7th)¶

Solution Cryptography¶